Here's a few things to avoid when Rp'ing with others:

-The people who never miss a single shot no matter how hard it is. Dont do it, it is annoying! (Aimbotters).

-The people who can't be hit or just shrug it off, they are some of the worst (god-moders).

-The people who have absurdly strong powers (twinks).

-The people who 'balance' their characters by having an irrelevant weakness and massive powers (min-maxers).
I might be guilty of this xD

-The people who use Out Of Character knowledge to get an edge (Miss Cleos).
DO NOT DO THIS!!! Obviously its a big deal since you could easily read someone's profile and automatically know everything about their shikai and bankai if you wanted to, but if you're a fan of bleach you know that these things are BIG BIG BIG secrets, and besides it just doesn't make sense that your character would know something that YOU as a real person read in someone's character profile. Just keep in mind that your character and yourself are different and you can't read about someone's powers then have your character pull a "Hahahaha, I know all of your moves" omnihack

-The people who do things in hindsight (McFlys).

-The people who RP other people's characters for them (Puppetmasters).
I HATE this. My character is my own and nobody else tells him what to do or how to act.

-The people who RP completely irrelevant things (Daydreamers).
Ew. Just don't do this. It ruins things.

-The people who RP actions and time against others while the others aren't present OOC, but are IC (Shoe elves).
Basically...take turns mmkay?

-The people who ignore or alter RPs that they don't like (Revisionists).
Mods, please do not abuse your powers. I know the edit button is lots of fun but just because you can edit other's posts doesn't mean you should...even though I do for laughs from time to time x3

-The people who RP an absurdly time consuming sequence occuring between other people's actions (Speedhackers).
Even experienced roleplayers do this. It does not make you a better roleplayer to post an insanely time-consuming post describing the actions your character took over several hours, and it annoys the hell out of everyone else when it leaves their characters in your proverbial dust.

-The people who play as characters that are completely impossible (Oxymorons).

-The people who arbitrarily declare themselves the winner with instant death attacks (Baghdad Bobbits).

-The people who've taken actions before they start RPing (Gaseous Snakes).
...I don't really understand this one but don't do it regardless.

-The people who pull in elements that were approved in an unrelated RP (Augustines).
You generally won't have to worry about this since anything you're approved for in this guild applies all throughout the guild...the exception being special weapons or tools your character might create, which need to be approved just like the rest of your 'powers'

-The people who use an existing persona and only RP them when it helps (Batmen).
I guess this means you can't have a guardian angel watching over your character. ...Its okay if it makes sense, like how Ichigo's hollow takes over whenever he's about to die, but generally don't do it as its bad for roleplay to have Batman grappeling in every time you get in trouble.

-The people who alter their character as needed for the situation (Zoicite).
DO NOT DO THIS. Be consistent. Stick to your guns, and by guns I mean the powers your character has and was approved for. If you wanna make changes to your character make sure you get them approved before you use them and of course don't try to radically alter your character if you can't help it. I understand some people want to keep secrets (like shinigami who are actually arrancar or something like that), but at least keep your powers the same.

-The people who gain abilities as they need them with no prior exposure (Trinities).
Actually this is more or less okay to do here. As shinigami/arrancar/whatever your powers constantly grow as you train and fight, so don't be surprised if you suddenly get your shikai in the middle of a fight. Just make sure you don't go using a bunch of random powers you don't have or casting a lot of kidou you don't know.

-The people who pick-up things that spawn from seemingly nowhere (Quake-ers)
Lol, this is also okay to do, just make sure that it makes sense that thing would be there.