In general, figure out what you're looking for and be able to articulate it. Do you want long-term or short-term? Story heavy or random smut? What themes? What kinks? Do you want to RP in a group? One on one? In a thread? On a messenger? On a casual basis, or posting daily?
If you know what you want and can lay it out clearly, then you should have no problem putting up a decent request thread or reading through others to find what you want.
Put a tiny summary/hint of what you are looking for in the thread name (instantly catches the attention of your target audience), or organize your RT so that the essential details would be stated in the beginning.
Maybe it is just me, but since I like very specific kinks, its kinda hard to sort/find what I am looking for by reading every thread posted. People tend to make long personal introductions before they get to specific details, like the ones mentioned by Shiver. There is nothing wrong with introductions, they are needed. But many times I read a thread, got enthralled with the person, their style, character, wit.. and when finally reached availability/kinks/etc. info, it completely mismatched with mine. So I kinda stopped reading long threads that don't get to the point fast enough. Again, personal opinion here!