Hit up on Par 3’s, and hit second shots on par 5’s to 90 yards rather than going for the green (this will save time and strokes), and if you ride in a cart, after a shot, do not put your club in the bag, just keep it in your hand and drive away. Put the club in the bag when you get your next club out of the bag.
Also, read LUCIUS RICCIO’S BOOK: THE PACE OF PLAY BIBLE.