Weddingdance makes a good point about the lifting of the heels. Latin hip motion is, among other things, a process of offsetting the hips so that one is higer and farther back than the other. The body, with it's built-in self-preservation, does not take kindly to unnatural or uncomfortable positions, and will automatically compensate wherever possible. So if you're not totally accustomed to the offset position of the hips, the lifting of your heel will provide enough compensation for the body to prevent any hip motion at all. So all you end up doing is picking up your heels, one at a time... sorta like a chicken!
So I definitely agree that the best way to familiarize your body with the positions involved in latin hip motion is to practice it with feet flat on the floor. Sooner or later, you'll be familir enough with the positions where you can take to them *and* lift the heels. But that will take some time.
Some other things to be aware of: Learn to straighten one knee completely before bending the other. You'll often lose the feeling the moment you have two bent knees, and then it can be difficult for a newcomer to get the feeling back without completely starting over.
Also, pay much more attention to your straight leg than to your bent leg. Is it really straight? Are you pressing it back? You may notice that you haven't truly been straightening your straight leg, which will greatly limit the range of motion of your hips. Have a friend put his/her hand against the back of each knee as it straightens and push your knee back against it. You'll notice that this pushes not only the knee, but also the hip up and back.
Finally, realize that positioning is only half the game... the other half is coordination of the bent/straight action to the placement of the step. This part of the process is a little more complicated, and will take some time to develop. The best thing is private lessons, but if that's not possible, then don't work too hard at it. Parctice your positioning diligently, but not the coordination. You stand to make things worse than better. Instead, allow it to permeate your brain and your dancing naturally.
I hope this helps.
Oh, by the way, we have a previous lesson from Ballroomdancers.com available on the topic of latin hip motion (specifically the positioning part of it). Transcipts of previous lessons can be ordered for $5 each. Visit the website and click on the link to the sponsorship page if you're interested.
Sincerely,
Jonathan Atkinson www.ballroomdancers.com
