Plie

At all times imagine a straight rod running from the closed heels to the tailbone, to the top of one's head, all the way to the ceiling.

1. contract abdominal and butt
2. tuck in tail bone
3. with a full turnout, bring the tailbone toward the heels
4. as the knees bend and the tailbone is lowered, heels must rest on the floor until you cannot lower further. Only then are the heels released.
5. Vice versa as knees return to stretch position.