To get great results on the golf course, focus on impact and follow-through, not your backswing.
Be consistent with your tempo. Make a swing with your favorite iron, find your tempo, and then use the same with your driver.
To control trajectory, practice using a sand wedge to hit a low shot followed by a high shot. Play around and experience this same drill with other clubs.
If you are having trouble getting your hips out of the way and swinging over the top, this drill will help. Practice using different clubs.