One key is to keep the weight into your palm even on your backswing. You don’t want to sway backwards with your backswing and ease up on the pressure into the table with your bridge hand. So especially with your last backswing, lean forward into your bridge hand as you pull the cue back. When you start your swing into and through the cue ball, your hand will already be snugly in place allowing you to exert your sledgehammer break into the stack.
After you contact the cue ball it is ok to take your hand off the table in classic Johnny Archer style, but not before. Or just leave your hand there and follow through like Earl Strickland. When breaking from the bed of the table, you also want your bridge palm planted snugly into the table with some more of your body weight than usual. You can even turn your hand more sideways and clump your fingers together to make a more solid bridge.
Another thing I like to do is look at the cue ball during my actual break stroke. Because really, you need to hit the cue ball really hard, not the rack. So I concentrate on lining up accurately and getting balanced in my set up and warm up strokes, and once I think I’m on line and solid enough, I’ll look at the cue ball and send it.
I also like to bring my front foot closer to the stroking line when I break. This allows me to shift my weight forward and keep my balance at the same time. Well, see if any of this adds power and accuracy to your break.

