The golf swing is hands down one of if not thee hardest athletic move in sports. One simple miss queue between hands, body, feet or head will throw everything off. Here are 3 drills to make sure you are on plane every time. First I want you to set up to the ball like you normally would. Instead of your normal swing I want you to only turn your body on your back swing until your club is parallel to the ground, then from there I want you to swing through to where your club is parallel to the ground on your follow through. Repeat this move over and over and over. You can even do this while watching your favorite tv show. Doing this will make sure you start on the right plane. When done properly you should see your club making a c on the ground.
Next drill is lay a club on the ground where the ball lines up and lay another club on the ground down your target line at your feet. Swing back till your club is parallel to the ground and make sure your club is directly above the club you laid at your feet. If it is good job than swing your club up till the but end points at the ground. If you are on plane the but end of the club should point directly at the club you laid on the ground where the ball is. If you can get there then your backswing is looking great.
The next drill is slightly frustrating. I want you to put 3 golf balls on the ground in a 45 degree angle, then set up so you will hit the middle ball. I suggest leaving a good distance between the balls when you first start this drill and slowly move them closer as you get more comfortable. When I started this drill I found it very hard to concentrate on the one ball, it is very overwhelming. As you hit that middle ball you should feel like you are swing through the gate you created. This drill will keep you on the inside to out swing path. If you hit either of the other two balls than you weren't on the right plane. If you practice theses drills every time you go to the driving range you will be getting better and hitting longer straighter drives ever day. Keep practicing and you'll be able to take that money from your friends any day of the week!