This is a great drill focused on the separation of upper and lower body, created through coiling and counterbalancing.
The drill is named after Erik Schlopy.
Leave your poles and, at the start of every turn, place the outside hand on the outside hip and push the hip to the inside of the turn and keep the inside hand pointing up and forward.
Keep pushing the hip to the inside and thus increasing the Counterbalancing in every turn.
MORE and MORE. Then a little MORE.
Focus also on counteracting as the skis are tipped on edge and come around the turn.
The inside hand held higher contributes to keeping the shoulders level (and not drop in to the turn). You can progress to pointing the inside hand not just forward down the hill, but even to the outside, to exaggerate the separation.
It is important, when doing this drill, to not rotate with the skis, i.e. make sure the inside hand does not point all the time to where the skis are pointing. The hand may point in the same direction as the skis, briefly, as the skis continue changing direction through the arc.
Also, do not "park and ride", i.e. get into a static countered relationship at the beginning of the turn and stay there - continue to counteract throughout the turn, so the hand keeps pointing roughly down the hill.
When reviewing the video or have a partner watch your execution, make sure the hips and shoulders follow the hand, i.e. the they stay pointing where the hand is pointing.
An even more extreme form you can progress to is the Outside boot touch with a twist.