One thing I was thinking on last night.
One reason I like to present as a female online is I generally enjoy people "treating" me as a girl. It is not like they treating me like some china doll, but they will say things, act a different way then if they think I am a guy. The amazing thing is I don't act any differently, as in I don't have "boy mode" "girl mode". I will say and do things regardless what people see me as, but again one reasons is I just really like people to "see and think" of me as female online. (When I can get away with it, that is the main issue being per-everything.)
So maybe ask yourself how do you want the world see you, try experimenting online if you haven't see if you like it more when people see you as a boy or a girl, or even openly state that your transgender. (It is the most wonderful thing about the internet is you can be anonymous - it is also the worse thing buuut that is a different topic all together.))