My favorite drill for getting more distance on your driver, is to strengthen your torso. You simply hold a 5lb or a 10lb free weight tightly against your chest , get into your ready position and rotate as if you were making a golf swing without using your hands, arms and club. Make a full or partial swing movement in slow motion, reset and repeat. Three reps of ten twice a day. Distance will follow.
The key to your success with this drill, and all drills, is to “practice with a purpose or a specific goal”. To practice with a purpose means to have a specific goal or an objective in your mind and focus on that objective.