Updating my response upthread, based on experience teaching this year.
The idea of foot tipping remains fundamental, and yes, it starts from the feet (pretty much by definition). But many students run into trouble because they block the movement due to lack of fluidity in the hip joints. Action at the level of the feet needs to be complemented with turning of the femurs in the hip sockets.
If a skier only tips the feet, the skier will fall over. So the skier naturally does something to avoid this, and unfortunately that something is often to stop tipping. To enable tipping, there needs to be a balancing movement higher up the chain, and this requires that turning of the femurs.
The idea of foot tipping remains fundamental, and yes, it starts from the feet (pretty much by definition). But many students run into trouble because they block the movement due to lack of fluidity in the hip joints. Action at the level of the feet needs to be complemented with turning of the femurs in the hip sockets.
If a skier only tips the feet, the skier will fall over. So the skier naturally does something to avoid this, and unfortunately that something is often to stop tipping. To enable tipping, there needs to be a balancing movement higher up the chain, and this requires that turning of the femurs.