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
Etiquette is important on the golf course, especially when it comes to following the rules, so learn to mark your ball correctly so you do not incur a penalty
Start with a neutral grip making sure that your left hand is not turned over or under the shaft, this will prevent you from manipulation the clubface at the top of the backswing