Stand while holding a club in front of you. Then rotate side to side. Move fluidly and slowly. Don't force anything or, if there is pain, stop. Keep the stretch going for 30 rotations back and forth. This will help to allow a release of the back muscles that will be used in the golf swing.
A simple arm stretch that can be done to increase flexibility of the arms and shoulders is where you bring one arm across your body and then push the wrist of your other on that arm. Push it as you were trying to push it through your body. This stretch will be felt in the outside of the shoulders as well as in the upper arm. Hold this stretch for 20 seconds on each arm.
A few stretches that can be completed to increase flexibility are to first touch your toes and hold for 20 seconds. Then bring one foot to your butt and hold. This is for a quad stretch. Hold for 20 seconds on each leg. Then find a tree or immovable object and lean against it with your legs out behind you. This will stretch the calves. Hold for 20 seconds. Doing these stretches routinely will help to create a more flexible and dynamic golfer. Always remember not to force anything, but aim for a comfortable pull.