Practice hitting long putts with just your trail hand in order to get a feel for the putter's flow and eliminate hip action in your stroke
Grip strengths are categorized as strong, standard and weak; select one that is best for you and learn to groove your swing with it
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