I think if you are the bottom the best thing to do is find someone who is generally compatible and, when you have got to the point where you are getting serious and think they are too, tell them what you want and need. (Or at whatever point it seems comfortable to do so). Because I think even a mostly vanilla top, who cares about you, will gradually be able to top you to give you what you want. (This won't work for someone seeking a fantasy spanking romance style top who, due to their awesome innnate topness, "just knows" what the bottom needs. But in real life, with realistic expectations, there is an excellent chance it will work out).
I think it is a little more problematic if you are a top. For TTWD to work on a long term basis, the person who is to be the bottom must be fairly bottom oriented. A partner needs to be at least mildly bottom oriented in order to react well to topping, especially on a long term basis. I think it makes some sense to look for people who already know they want a partner who will top them.
On the other hand, any amount of time reading boards dealing with DD, TTWD, Taken in hand, etc. will reveals that plenty of couples discover their affinity for DD after they have already been together. And while I hate to say it (because I can identify with tops looking for bottoms for serious relationships) I would be wary of those who advertise themselves as such, especially if they are men (not sure what your orientation is). Lots of creeps and jerks out there.