OPEN LEGS, on the STAIRS -- or up on a KITCHEN CABINET (or bathroom vanity)
 

Other similar poses allowed, as long as the concept is similar -- subject is elevated (relative to camera height) with legs open, or subject is lower (relative to height of the camera) with legs open.

It's the camera angle, and the fact that the subject can sit comfortably (without leaning back or laying back) that makes this pose work so well.

Some examples...