One of the biggest changes to Francesco Molinaris swing, which is responsible for his recent success, is the change to allowing his left heel to lift off the ground in the backswing.
This move is one that I've always encouraged for golfers in my teaching career. It is often overlooked but it allows the hips and shoulders to complete their rotation on the backswing, this leads to better ball striking and increased distance. It is also a great way to start your downswing by placing the left heel down as your downswing trigger.
As well as Molinari, Jack Nicklaus and Tom Watson were both great exponents of this move, and they won a few tournaments!
Please note, the left heel is lifted due to good body rotation, not lifted independently.