"Hi, I'm a submissive and I want to book a session with you.  My interests are blah, blah, and blah (and I expect you do it if we play)"...

that is what is wrong with this website...very few actual submissives and dominants as it's a virtual domination drive thru.  

"Hi there may I take your order...and may I offer you a side activity of spanking to go along with your session today".

Find out what a dominant likes (to make sure you re compatible), set-up some ground rules for limits and safe words but once you cross that doorway, I just believe you should let her do whatever it is she wants....after all, you are a submissive.

That's how I play and I have had some mind blowing sessions as spontaneity is the foundation to any great session.  After all, do you really want it to be like a choreographed dance number?