Playing a deep inside line for me usually means that I should curl or at least tuck my pinky finger, spread out my index finger as much as I can, and do one of two things with my wrist:
A) Keep wrist cocked and hand directly underneath ball if there is alot of head oil and you just need to tilt the ball enough to kick out the corners
B) Cock wrist and put hand completely on side of ball if you need more skid through the heads.
The main thing is to stay relaxed and don't try to turn the ball any more than normal. If you do you'll just end up either coming up the back of it and it will hit light, or you'll spin the ball and it may miss the breakpoint completely.
