To be fair, I recall stirring up plenty of shit with my metagaming shenanigans back in the day. To help counteract this, I'd recommend (purely from my own experience mind you) to focus on one of two extremes.
The one I've gone with is essentially focus entirely on the character. Focus only on their desires as a character, and not yours as a player. That way your actions have full justification behind them even if they do end up being somewhat assholish, but you can't go on random shenanigans if your character isn't that type. It does require a lot of thought on what your character would do in the situation at hand, if they have any plans for the future, and such though.
Or you can go to the other end and discard their character entirely - stop acting in accordance to backstory or anything else and just do what you want to do. Grants you freedom of action since you can basically do whatever the hell you want (doesn't guarantee your success but if you wanna go look up alien species on the space Internet without having an IC reason to do so, there's your solution).
Don't have to do either, it's just the path I ended up proceeding along after my rather rough start. Most importantly regardless of whatever you end up doing, though, is I'd say to realize people's ... existentialism? Capacity to do actions and possibly prevent yours.
For instance, say you wanna extract a person's blood for no clear reason. That's fine, people have done worse before. But when doing that action, just make sure you remember that they're likely to object to surprise blood extraction - but that interplay - 'hey man why you tryna stab me' 'I wanna extract some blood from you' 'the fuck, why' 'mad science involving unstable alien artifacts, don't worry it'll only kill me at best' - that IC explanation by your character as to why they're doing this random action is the thing that makes for good interaction - because even if it's confrontational, it's interesting.
Rambling done!