Scans/Canon: Posting the actual legit scans is helpful mostly for Manga and comic debates posting scans helps in all ways from there, Combat to their actual Canon powers and abilities like example of Kami Tenchi apparent Omnipotence which isn't in any way proven to be a fact so scans are important in any debate specially of powers and most best feats they got (Or less whichever helps the user).
Explanations: Mostly people need to explain in perfect detail of the characters meaning if someone has no detail of their power's or the history explain it, a fine example of a character is the questionable omnipotent being known as Azathoth a being in LoveCraft people hardly know of and explaining in detail is helpful because it helps others grasp the character abilities, background or even weaknesses that comes with the character, but just making fan assumptions/speculations a common bad debating method.
Proven Abilities: If the character hasn't shown the actual abilities then its plain hyperbole people argue about Official Omnipotent beings like The Presence or The-One-Above-All but these beings proven their status as Omnipotent beings of their respected Omniverse and has all powers known to their own omniverses.
Official Author Statements: In interviews author's answer questions about said characters or other questions to satisfy our minds like Marvel writers officially saying and stating a character is Omnipotent like Beyonder or The-One-Above-All but TOAA being the absolute God due to Beyonder being retcon from his original origins. Answers from authors help with debates so people won't argue that much over a fictional character's feats and other information. Or how about Kami Tenchi creator stating Tenchi Masaki is his avatar in the series but never claimed he is the Absolute Supreme Being or his avatar. In any possible way its known as false author statements. However, some of author statements may only add fuel to the fire, like statement of whole race of Celestialsapiens being Omnipotent, even through it goes against all ingrained knowledge of Omnipotence.
Universe Vs Universe: Basically like DC Vs Marvel making a good amount of restrictions and details for the battle is at an all-time importance like Thanos with Infinity Gauntlet vs Superman Prime only problem is the actual IG is only allowed and works in the Marvel Universe most likely the Earth-616 and is useless outside its universe so making sure the battle is in the location of the right marvel universe, in order to make it work is a good idea.
Non-Fan Based Opinions: To show a non-biased or non-favorite opinion or standpoint in a debate namely in the famous Goku Vs Superman death battles now it is hard to debate with both the Supertards and Dbztards, but standing a neutral ground would seriously help the debate since no one is saying a huge assumption, speculation, and or making up theories on who wins.
Fanboyism: Like fanboying over characters who are basically hax or so hype they will be used over and over again! Fanboyism isn't fun on a debate forum/group as it causes arguments and uncalled for opinions an example of this is Beerus being, a Solar System or galaxy level buster even though it was only mentioned and not shown and fan boy's use this as an excuse to say other beings from DBZ are on this level because of Powerscaling.
Hyperbole: Basically this means that the character is all hyped up like a mix of Fanboyism+Wanking as people tend on stating random scientific terms for characters like again Kami Tenchi who has been said to be above infinity and gives him properties of being potential Omni level which isn't at all true and, if the character hasn't shown any actual feats or have been in an official databook , handbook, and or source then don't use them.
Trolling: People say people are trolling without knowing the true meaning of a troll its "Someone who tries to start unwanted arguments with other users for no reason and tends to get off topic purposely and intend to make people, mad either by comments or posting memes." ← True Definition (Not game trolling meaning.)
Insulting: Insulting others over a comment or a simple non-factual opinion is downright ignorant and childish if you can't handle a statement Factual or not you aren't worth a piece of paper unless he/she insults you first then by all means you have the right to be rude.Assumptions: Mostly known as a derived speculation where an individual would make a story to fit their character winning an example of this would be: "Well how fast is the flash people? He lost to slow beings and giving the rules Goku wins against the flash with speed blitz this is due to instant transmission, which is stated by DBZ wiki as Faster Than Light." this is just an assumption made by a DBZtard as Instant transmission is pure teleportation and not Actual Speed and therefore not a cited fact/feat.
Biased: Showing favoritism on a single character,team, and or race because you only know more about the said characters,team,race, and the weapons making you more likely to fanboy.
False Scan(s): Scans like Obito Uchiha beating The Living Tribunal or false VIZ scans so don't take MangaPanda or Mangafox or Manga Search images people mostly get scans they think is fake like Madara stating his Susano'o can smash up anything in the universe people deny his claim, but it's actually a real statement both manga and anime wise.
Unproven Author Statements: "Basically a combination of all three when debaters create false statements by author's and try to prove people wrong like Akira "Making Goku Omnipotent" or "Demonbane is omnipotent by the author." Which turns our fake and untrue as the person would 100% not upload a link or image to the claims they made so asking for Official Links/Images of this will be handy in the future.
Excuses: When a user try's to defend or justify why their characters win's or loses like a Dbztards with Goku always stating an excuse to post feats because they mostly use Powerscaling+Calculations to justify why he would win like "Goku wins by blowing up the planet."but upon this if you asked "How could he? and Why would he?" they will make an excuse to change the course and contradict themselves like. "Goku would just pull a vegeta." even when he is a hero and wouldn't destroy a planet to win or "Goku is a good guy he has morals he doesn't destroy planets."' only making an excuse not to show a specific feat.
Omnipotent Vs Omnipotent: A very bad debate since it turns into something called a Stalemate so using 2 Omnipotent beings against each other isn't Logical but!!! Making a Vote system saying who is better or who showed more feats are also good debates.
Movie/Fillers/Games: Like the most infamous DBZ character Broly who has and is a good example has been in both Movies and in Game fillers and in-game he is Non-Canon in the DBZ Multiverse and if the battle isn't about his Game or Movie versions, then he is featless by far and like a user saying "This is anime version Broly." ← But problem is there's no anime just only games and movie version. Or his filler appearance like him facing Gogeta& Vegito making people claim "Oh he is on par with them." This honestly is unknown asking Akira himself could only hold the truth.
Novel: (Honestly don't get novels as much, but this is what I can sum up so this is optional by far.) Like the Layfon novels which people say he is Light Speed+Continent level, but no one hasn't shown official pages or images then it's just like hyperbole because the person is basically making exaggerated claims from the novel and like other based novels like Vladimir Tod (The Chronicles Vladimir Tod) and much others are hard to describe there actual powers as there is no images or known media of them showing this unlike the new Vampire Hunter D series coming out soon. (Honestly don't get novels as much, but this is what i can sum up so this is optional by far.)
OVA's: Again this is optional as there can be a bunch of fake OVAS by expert fans or by a different author, but looking at Credits will be helpful and explanations as well since some people have trouble comprehending so in clean and clear detail about the OVA is helpful if the OVA is canon or not it's a straight anime series and statements by the author are highly primary source.*Game Cross Overs: Like video games in Japan where they have character like Naruto Uzumaki Vs Goku or Monkey D. Luffy Vs Naruto or the most recently hyped Ichigo Kurosaki Vs Luffy it's honestly unknown if it's official or fan made.
Raging Battles: Very known in many forums is the fights between 2 or more characters like Goku Vs Superman (Post Crisis) are a nice thread attention specially with people who isn't Dbztards or Supertards but this can also cause mayhem on the forum as many sites ban such fights because the fanbases get to personal,childish, and useless.
Crossovers: Examples is He-Man Vs Superman aren't canon and as such feats are useless within a debate.