If you want to hit the golf ball further with your swing, there is a point where we just have to say, you just got to muscle up and try a little bit harder. Here's a great drill to help you with that feeling. Take two golf clubs, make sure your golf clubs are fine, grip them as well as you can and hold them low down so they're well off the floor when you make your swing, and besides, the fact that you don't want the clubs to hit the ground because the shafts will wobble together, it could damage the shafts.
So, you grip them and lift them off the floor. Then, go ahead and make a series of 10 swings, gradually getting quicker. You start off with a slow little half swing and then build it up faster and faster until it comes into a full length back swing, full length swing-through. You'll feel your muscles have to work really hard to hold the golf club on both sides. If it gets quicker and quicker, the momentum, the centrifugal force is more powerful. Then, go back down to one golf club and just feel now how light this is.
Firstly, you've got a lot of control over this golf club. Secondly, you can feel how strong your muscles could be in order to generate as much power as possible, so, utilizing a two club sort of warming up drill and a way of generating extra power. It makes you feel how powerful your body can be with your golf swing. So, when you go back to a single golf club, you feel there's a bit of extra zip in there.
I would do this every time I'm warming up and practicing and also in the middle of my practice session, before I take my driver, a couple of two club swings. Do drills where you take two clubs, swing it 10 times, start off slowly, generating more speed and then feel how strong you can be for extra power with your big drives.