There are four keys to the correct grip: placement, positioning, pressure and precision. Check these four things every time and you will have a solid grip
Do not practice before a round the same way you would if you were working on your mechanics, get target oriented and play a few shots with ever odd or even club to a target, then play with the swing you have that day do not try to change it prior to the round
When you grip your club with your left hand the two middle fingers should just touch the pad of your hand