Okay, so back to hip motion: I think (and jump in here please 'cause this is really a question) that club dancers move their hips differently than "classically" trained dancers. It seems to me that club dancers are less formal or strict about the motion and there are as many styles as there are dancers. My instructor has broken Latin hip motion (starts with the feet and knees) into 3 parts (this is lower body only--we haven't gotten to the ribs, etc yet ) and I'll post this if I can figure out how to write it succinctly. And, if I understood him correctly, you practice the same motion for rumba, salsa, cha-cha, etc., but it looks different in the different dances because at faster tempos you can't do all the parts of the motion while at slow tempos it can be very exaggerated. You can also vary the look by making parts of the motion staccato. What an interesting technique to work on!