The hips do drive the shoulders which turn the arms, but most have no real feel for opening their hips on their bhs, earlier, so that their locked wrists can "drag" along after the hips. This accelerates their true power like throwing a frisbee, or loading a karate chop, the master opens the hips way early while "dragging" all else behind, as if all your weight is being dragged. The more weight you load up to drag, the more of a weapon your bh will become. If you don't feel the smooth weapon like certainty of the "dragged" hips, you are not ever going to develop a consistency nor a weapon. And it's the smoothness which adds speed, flexibility, power to the hip opening quicker/faster/deadlier. A quick firing hip open will solve a lot.
You learned with your one hander to close off your stance, which is more nec. than with a two hander. The two hander has both shoulders in play, and both hands, so they can afford a more open stance, as they have their non dom. hand on the frame. Most one handers take the frame back on the throat with that hand, but I leave it on the handle, which allows a more leveraged, faster take back, without a "bunting" config.
Foot work first: 11 step types: Video of foot work
#1: The split step first: Advanced split step: Shot of advanced split step, which causes an immediate unit turn, with the left foot facing towards the side fence, and the right foot facing the net upon landing.
#2: The cross step second: Cross step: Running towards the plant step spot with cross steps.
#3: The plant foot third: Plant foot: Plant the rear left foot towards the side fence, and that will position your self to transfer weight into the ball with the hitting foot.
#4: The hitting foot fourth: Hitting foot: Step into the shot with the right foot, in a closed stance, facing the left net post.
#5: The recovery step last: Powering out of the hitting step with a pound it down on the ball of the rear left foot and back pedaling back into position and split step.
#6: How to tango step up to a short ball and hit the top spin shot: Video
#7: How to deal with a deep ball and still hit top spin: video
#8: How to deal with a deep high ball and still hit top spin: High incoming ball=high non dominant hand: video
#9: The double hop on a short ball: keeping our bodies stabilized on the move into the net. Video
#10: The side step: Most do this only on the forehand video
#11: Serve return foot work: Split step and cross and nail it. video