One of the most subtle power-robbing things you can do when you address the golf ball before a shot is to stand very rigid. Rigid swings are not fluid, they don’t allow for a smooth transition from one stage of the swing to another and, if nothing else, they just don’t look good. Being rigid at address can lead to a “herky-jerky” swing that inhibits solid ball contact. Hopefully you have a pre-shot routine that includes some amount of flexing or shoulder-rolling to help loosen you up before a shot. But that is generally done before you address the ball. To help ensure a fluid, easy, free swing once you address the ball you may want to consider adding some sort of trigger movement to start your swing.
What is a trigger movement? Just about any slight movement that does not cause you to assume bad posture or a poor grip that you do just before you start each swing. Some golfers move their hands ever so slightly towards their target before beginning their backswing. Some may turn their head just a “smidge” to the right (for a right handed golfer). Some may draw their back knee (right knee for a right handed golfer) just a bit in toward the golf ball. I have found that on a tee shot it helps me to lift my club just off the ground and hold it about an eighth of an inch off the ground for about one second before starting my takeaway. That way I don’t “drag” the club at the beginning of my swing and end up off plane before my club is two feet from my golf ball.
You may already have a trigger movement and don’t even realize it. Generally people develop one as much by instinct as by design. If you don’t think you have one ask your golfing buddies if they notice something you do just before you start each backswing. Or watch them and see if they use one. If you watch closely you will likely see that almost everyone uses some sort of trigger movement to start each golf backswing.