I guess in this respect I'm fortunate, not only among kinkies but among "normal" people too: I've been single for all my teen years, and have spent a lot of time exploring my sexuality solo, so I have a very good idea of what I like regardless of who I'll end up with in the future. I've heard of people who don't know who they are because they've never been single for any length of time, and always form their identity (at least partially) on what their partner likes. It's not a problem exclusive to submissives.

Of course, I know there are partner activities that I won't know if I like until I try them, but I'm good enough at reading myself that I'm sure I'll be able to tell the difference between my pleasure and my partner's.