Don't start with really high heels, 2" or 3" is plenty.
Walk on the ball of your foot to start with, minimizing the pressure on your heels. Be very careful on stairs, don't let your heels catch on the treads, again use the balls of your feet. Wear your heels in bed to get the feel of them.
Sit down and wobble about on your heels, it's fun and so sexy!
Start with full support heels. Avoid sling backs and peep toes.
Any heel which looks sexy will hurt, you have heard of "killer heels"?