My best advice I can give is immediate disclosure. It's for your sake, really. The kinda guy that will want to date a transgirl will see you as a woman even if they know right away, and the kinda guythat won't see you as a woman if they know immediately won't ever be able to see you as one, most likely. So honestly, you save yourself time, heartache etc by just being upfront. Note: this is for pre/non OP tgirls, post OP is a whole other ball game.
Bear in mind, my experience is in dating men sothats where my advice comes from. But honestly? I really haven't had less luck or attention with full disclosure, so it's a win/win. There's a couple ->-bleeped-<-s here and there but nothing I can't handle. All around,dating isn't really thaat hard now, if we're talking strictly in terms offinding hot guys to goout with.