The single one thing that I know that will increase revs is to be balanced at the foul line and post the shot.
You don't have to speed up, special drill layout, grips, no grips, hand position change, 5 step, 4 step, 3 step doesn't matter etc.......There's no easy trick that doesn't require effort by you.
All you have to do is be balanced at the foul line. Do not step off, do not hop. Be solid and firm at the release and post the shot.
If you set yourself up for balance at the release the second to last step of your approach you will automatically increase leverage and therefore revs.
Erin