To become more grounded and less "hoppy" in Latin (not just cha cha) you might first focus on keeping your feet in contact with the floor. One exercise that I found useful for illustrative purposes was to try and dance with bits of paper towels under my shoes. The objective is to keep them there -- you'll quickly find out if you're lifting your feet off the floor with this exercise! I wouldn't suggest doing this all of the time, but it's a good introduction to how it feels to be constant contact with the floor.
There are other concepts that might be helpful, though they're not concrete exercises like the above:
- Try to dance *under* the floor, rather than on the surface. Of course, it's physically impossible, but it's the idea that counts 
- Think of stroking your feet across the floor whenever possible, rather than lifting and placing them (there *will* be times when it's appropriate to lift/place -- your instructor should be able to tell you when that's the case). I like to think of how it feels when you draw a match across a surface to light it -- an action that's quick but not light (because of the pressure involved).
- Beyond the feet, being grounded is about your entire body. I don't know where you are in your dancing, or if you've talked much about the use of your center. So, without getting too technical, I generally think of Latin as being solid and settled as opposed to light and bouncy. Use gravity to your advantage in Latin, and try to imagine that your whole body is connected to the floor.
Hmmm...hope that wasn't too obscure to be helpful!
Vanessa
