Here is a list I was working on for weeks to balance Yu-Gi-Oh; it's a lot of cards, but generally games can be won too easily via free removal/combos that is so powerful that drawing multiples rarely hurts you (like getting 2 Foolish Burials in your opening hand). It helps to limit total traps in a deck (including those restricted at their 1 or 2 respective copies) up to 8 while allowing weaker clone cards like I mentioned to at least balance things out; I could take off all those Zero Gravity clones off that list I have, like Windstorm of Etaqua. Even a trap deck like Uria, Lord of Searing Flames could suffice with this and it would at least make free, one-turn stalling/position-switching cards give up something, such as a field clearing trap like Radiant Mirror Force or Needle Ceiling (with only 1 Royal Decree for this format and that unique side deck rule idea I'll mention next, this will balance things out). I also think there should be a new rule to allow one to shuffle cards in their hand back into the deck and redraw the same amount once before starting the game after they draw their initial 5 cards, to get rid of the problem of drawing multiple Thunder Dragon, Destiny Hero - Malicious, or drawing all/no monsters which pretty much guarantee a loss solely due to bad luck.
I'd probably have a side deck rule for 15 different cards to actually give running a theme a chance rather than splice your deck with the most powerful cards. Think of it this way: many restrictions in the Advance Format undermine themselves. Restricting Smashing Ground is pointless because I can also use Torrential Tribute, Fissure, and Bottomless Trap Hole for free 1 shot removals or Dark Armed Dragon, and Snipe Hunter for monsters (who would stay on the field after removal) to wipe monsters, spells, and traps. In other words, restricting cards that nearly copy one another (to the point of being abused in any deck) is the same thing as allowing 2 or 3 copies of one of the cards.
The game is so fast-paced (even in the format I made up) that I sometimes don't even get a chance to summon multiple Synchro Monsters, especially of the same level. Advanced Ritual Art with 3 Manju of the Ten Thousand Hands to search for either the spell or the monster makes restricting any ritual monster, like Demise, King of Armageddon, pointless. I got tired of playing by Advance rules, using an especially boring Raiza lock deck, to which I'd actually keep tribute summoning Raiza the Storm Monarch on consecutive turns to directly attack and remove their monster; it makes me feel sorry for my opponent when I start off with one and have one of my 2 Foolish Burials I mentioned in my 1st paragraph to let me special summon Wulf, Lightsworn Beast and tribute it for Raiza turn one if I go 2nd.
Given the fast pace of Yugioh with all the new draw cards like Destiny Draw, Allure of Darkness, etc., losing a draw phase is crucial and needs a cost like Back to Square One (though I'd still restrict it since you can combo your discards or use this with Destiny Hero - Diamond Dude for free. It also bypasses any sort of protection from excluding targeting/being unaffected) to balance it; unlike that card, Raiza stays on the field and has 2400 attack to ward off any weak or nomi/tribute monsters my opponent may play. Just creating this deck I mentioned pretty much makes creating any kind of themed deck that doesn't one-turn kill completely pointless. For example, Raiza is stronger than any playable zombie (Despair from the Dark and Vampire Genesis are both pointless cards given their work to summon and/or lack of a powerful effect) and zombies in general do not remove monsters unless you have Plaguespreader Zombie synchro summon.
I mentioned that each card in a side deck should be different because it really creates an unfair mismatch should someone just abuse situational cards that would exclusively take down your deck, like 3 Light-Imprisoning Mirrors if you're running Lightsworns, making it pointless to go strict with that theme because they just became normal monsters and lose their self-milling; it's about as frustrating as playing a burn deck against one who uses 3 Des Wombat or 3 Prime Material Dragon and having to just play to counter rather than enjoy actual surprises (like one using Dark Magic Attack in a Dark Magician deck) rather than blatant field clearing every turn/one-turn kills every game.
Creating a ban list to duel casually (after all if you've done this, you quit on formal dueling at tournaments), is difficult. If your luck is as bad as mine, people will stand you up when they say they'd play against you with it, or they'll actually try to pick a fight with you for just suggesting the idea due to some blind devotion. I remember one person actually had so much faith in their (15 card) side deck in regards to the game's lack of balance that they believed that I'm only making this idea solely because I'm losing, which isn't true at all plus it's a condescending way to act towards a new idea.
Winning or losing to sheer luck in one or 2 turns makes playing the game pointless in my opinion since the game just went to auto-pilot because easy monster theft/unbalanced swarming/field clearing can make anyone's hand completely irrelevant. You can do many alternatives to the Batteryman OTK should turn 1 you play Giant Trunade or Heavy Storm and Brain Control to steal their monster and tribute summon Batteryman Charger while playing Inferno Reckless Summon for 3 Batteryman AA or play special summon Cyber Dragon and another monster and play 2 or 3 copies of Honest if they summoned something like Stardust Dragon. Many decks have different versions of this scenario, making too many decks outdated.
Even if you can't get any regulars for a list you might make, you can at least explore the different decktypes on your own. I never thought that Kinetic Soldier would have so much support given DNA Surgery to turn every monster into a warrior so you can use Assault Armor, Mysterious Guard's effect, Warrior Elimination and Puppet Plant. This deck would never work in Advance Format, but at least it has potential with the format I created. It's also important to note that not every deck works even if Yu-Gi-Oh was completely balanced; Flying Fortress SKY FIRE, Gate Guardian, and Fire Princess are too difficult to use given how many cards do things easier, like fusing for Rainbow Neos, using self-milling with Judgment of Pharaoh, or use Volcanic respectively, even if you balance it.
Some decks need to be played for combos, like Archfiend of Gilfer with Peten the Dark Clown using Dark World Dealings or Dark World Lightning rather than use Dark World or other Archfiend monsters except for Kahkki, Guerilla of Dark World and those Archfiend synchros like Thought Ruler Archfiend; this makes Falling Down playable. Psychic need self-milling, so cards like Card Trooper would be a good idea to revive/remove those psychics from play to get those effects. I mention this because stacking up your deck with weak effects like Goldd, Wu-Lord of Dark World, Sillva, Warlord of Dark World, and Broww, Huntsman of Dark World are completely worthless when the opponent summons something better due to all the special/synchro summons available. It makes them practically normal monsters, especially if you revive them with Gateway to Dark World. Broww is worse to use then Peten because it's a deck thinner that doesn't stall the field nor does it work if it was sent from your deck to the graveyard, such as with Foolish Burial, unlike Peten.
Even if we got rid of the free removals, there's still plenty of things to use to get rid of any monster, making every deck need to have some sort of speed; they need to inflict damage quickly (Burn), swarm/summon in 1-2 turns, clear the field instantly (like if you have Guardian Sphinx with Vengeful Bog Spirit, or have some capable alternate win scenario like milling given Needle Worm or Morphing Jar and Book of Moon/Book of Taiyou/Book of Eclipse or Final Countdown with a lot of stalling including the chainable Scapegoat and Waboku in addition to deck thinners and Gold Sarcophagus to get that countdown beginning as soon as possible. Some decks can do all of these, like if you used D.D. Dynamite in a Macro Cosmos deck with Chaos End, Necroface, and D.D. Survivor.
I created a lot of deck creation articles because of new combos I found in this format I developed since I couldn't abuse the old ones that were far too overpowered; I think that deck-building is the most important part to a trading card game, but it needs to allow room for thought. However, I'm not talking about netdecking, where one just blindly copies a tournament winner. I'm just saying one shouldn't have to use cards that will always bail them out because it becomes abusive. For example, using 3 E - Emergency Call and 1 Reinforcement of the Army pretty much took out a lot of guesswork in building that Elemental Hero deck; you don't even have to try to build a deck given how those 4 cards in the same deck will never be a bad draw no matter what your opponent has. A fifth card in that deck would obviously be the restricted Elemental Hero Stratos.
The hardest part of making a ban list is to see how your old changes react to new ones; for example, Hamon, Lord of Striking Thunder is not overpowered without Megamorph, plus you can't get all your crystal beasts in your spell/trap zone in 1 turn. Generally for my list: banned cards are clones or work too well (like Lightning Vortex compared to Special Hurricane, Needle Ceiling or Giant Trap Hole because you have no risk and it takes no timing/effort to use), restrictions are for cards that work by themselves (or can be easily put in multiple decks/salvage a terrible hand by itself) or can set up an easy win (like Burial from a Different Dimension) through a combo that has little difficulty to get off, but isn't unbeatable. Semi-restrictions are for cards that can be a pain at 3; they're cards that you can't tolerate happening every turn but once per duel is fine. In general, I made removal at least cost you something, such as losing a monster or discarding a card if it wasn't situational. Revival needed to be temporary or have some cost or else were limited if they were based on a theme. I also made sure that cards you dump from your deck to graveyard or add to your hand cost you your normal summon or else were limited (since using Light of Redemption is faster than Dimensional Alchemist and Foolish Burial is faster than Armageddon Knight).
New sets make for a lot of changes in the game. I realized from Stardust Overdrive that Dark Simorgh really makes the game a lot faster, though it isn't too unfair at 1 copy. It made me change a lot of my list as it is, taking off many cards either completely or moving them up a notch. I noticed that Chain Strike really needs you to get off Morphing Jar to work well or else you'll run out of ammo (since I'm allowing a max of 8 traps, so you'll have to reload at the cost of some protection should you use traps that let you draw). Lava Golem also needs to have its setup with cards like Magic Cylinder or Amazoness Swordswoman with Mist Body; it can still lose to a swarm, plus I do allow Judgment Dragon at 1 (which a Lightsworns deck needs to have a chance with its only other support being Celestia, Lightsworn Angel, which I obviously restricted). It is interesting to note how well Bad Reaction to Simochi works with Gravekeepers, but there are times you can get bad draws, so it's balanced. Also, that trap rule I have pretty much makes you have to give up something for that potential (yet very rare) possibility of an OTK with the 3 copies of Gift Card. Comparisons always help when it comes to making decisions about banning/restricting certain cards; they let you get an idea to know how powerful they are.
Only by testplaying a lot can one figure out how cards can work; fortunately you can do this online using programs like YVD (better filters but lacks a solitaire mode for 2 decks) and LackeyCCG (worse card filters but has a solitaire mode, so you can combine for both) to form 2 decks to play Yu-Gi-Oh in a solitaire fashion. I mention the card filters because there are over 3,000 cards made and the purpose of creating a ban list is to explore every one of these, to see if the things you take out, like me with Heavy Storm, can be replaced.
Balancing combos mean the draw cards that let you cycle your hand are not as overpowered, with the exceptions of Allure of Darkness (remove from play Necroface or use Escape from the Dark Dimension, but with those restricted, it's not that powerful) and Gladiator Beast's Respite (cycling your hand lets you use Gladiator Beast Murmillo or Gladiator Beast Alexander rather than have them stuck as dead draws; it combos far better than Trade-In and the like since it's 3 cards too), which I think Respite needs to be semi'd. However, Six Samurai United is practically a Pot of Greed if you get Grandmaster of the Six Samurai in your hand and do 2 summons in the same turn, hence its restriction. Removing all the free monster removal (that have hardly any cost but work too well like Compulsory Evacuation Device and Bottomless Trap Hole) because decks that thrive upon removal with discard costs like Gadgets or Ojamas make these unbalanced; Forced Back at least works superbly on normal tribute summons but can be fairly bypassed by a special summon.
You just need to find cards that work together consistently to quickly impede (using Twin-Sword Marauder or Dream Clown with position changing cards like Zero Gravity), or overwhelm (Solidarity with Ultimate Insect LV7) your opponent; using Armed Dragon does neither, making it a pointless deck to build since you need to discard (technically send to the graveyard) strong monsters to destroy only face up monsters (except for sluggish Armed Dragon LV10 where it's still face up monsters but you can discard any card you want) and it's worthless on your opponent's turn, by which comboing with Ojamagic or Gadgets does not bypass. In terms of a custom ban list, one must continuously update it when they discover things as I mentioned before. You also have to keep in mind that some decks age poorly, like VWXYZ, so testplay multiple feasible decks to balance the game to a level you are suitable with.