I am personally a demi-girl, so this might be half useful- (I'm hilarious, I know) But I would say we don't act any different then a cis-gender person! Depending on the temperment of the character, they may care more about being gendered properly, or brush it off- (For example, I really don't care much about being misgendered, but my partner, who is nonbinary, does, and will correct you.) I would wager to say if the character is AFAB, they would lean towards masucline clothing, and if they are AMAB, they would lean towards feminine clothing, but that is simply me, and my experiences!