I like to see a player putt the ball off the center of the putter – not back towards the golf putter’s toe.
The golf putter should be flat on the ground. Any grip that is comfortable or reasonably orthodox is all right. I don’t care much for a lot of wrists in putting.
An exercise that helps is to face the wall, put the top of your head against it and then stroke with the golf putter along the baseboard or skirting. This will help you feel swing path.