One of the keys to hitting the ball long and straight is having the proper release of your club at the point of impact. Amateurs commonly release the club too early, allowing the wrist to break and the impact of the ball to happen on the upswing, with very little of the body rotation force behind the club. Releasing at the proper time allows the wrists to stay cocked and loaded and body weight to play a major role in creating ball impact. There are drills you can do that help develop the feel of proper release.
Cross Handed Grip Drill
Take your traditional golf setup.
Switch your hands, so your lead hand is on the bottom of the grip and your non-lead hand is on the top.
Make half swings using your lead forearm to pull the club through. Notice how your lead wrist is bowed as you come to impact and releases as you go in to your follow through
Groove those little swings so the club head is passing through where the ball would be on a level plain, not on the way down or on the way up. To develop more feel for this, set a tee in the ground at your normal tee height and brush over it, just touching the top to make sure that your club is level on impact.
Tie a towel around the shaft of the driver, so that it sits just above the club head. This will increase the weight of your club.
Take several slow, full practice swings.
Look and see where your wrists are at the point of impact. For a proper release, your hands should be in front of the club head when the club head makes impact with the ball. To visualize, your hands would be off your lead hip as your club head goes through the impact zone.