You want to practice at different, equal "tempos". There is usually, a slight natural acceleration from the backswing to the downswing, but we do not want a slow backswing, then a rushed downswing or speed it up. So, if you want to turn through faster (a good thing), try to match the backswing, to the downswing tempo you imagine. So ,if you imagine a "tempo" 15% faster on the downswing for Driver... turn your shoulders on the backswing at the same pace so everything "gels" at the increased tempo. One visualization I use just before I hit is, to picture (in rhythm), the "finish of my backswing" (1)... then the "completely finished swing" (2). This is in (2) beats or "finish" (1), "finish" (2). Then I take a practice swing at the "pace" or "tempo" that I feel, to see that I can actually swing at the speed I'm imagining. Then if I like it... I move over to the ball and "repeat it". If I don't, I may slow both down equally until it feels right and doable. Then "trust" that rhythm and go.
Move Less ... Get Good! DUPLESSISGOLF