Learning how to master your backswing is going to play a very key role in your ability to actually have a great game of golf. Without a good backswing, it is going to be very difficult to actually have a good game. You can still play without a perfect backswing but improving your backswing will greatly improve your overall game just as much as mastering your putting. It is important before you start working to improve your backswing to remember the goal is not so much to improve your power, but rather improve your distance as well as form.
If you are starting with a good solid stances as you swing, which includes proper posture, as well as shoes and alignment with the ball you are going to have a much better attempt at improving your backswing. Without a good sturdy posture, you are going to twist at the wrong moment and even potentially have huge problems with not being able to really grasp the club properly. This combined together can create huge problems in a successful backswing. Your first line of defense is to always ensure you have the right stance, which will allow you to quickly and easily perform the appropriate follow through for your swing.
If you have any doubts about your stance take a picture with a camera, or ask someone else to take a picture. Then compare the proper stance with the exact way that you are standing. If this is not an option for you, look into some lessons, which will allow you to work with someone to truly master your stance. Building your skills upon a good set of foundation skills is necessary in order to ensure that you are learning the right skills as you need them. If you have the ability to work with an instructor this is going to be the best way since they can be much more honest with you about the flaws in your stance than you will be with yourself.
Your next set once you have corrected your stance is to look at the problems with your grip. If you are overextending your grip, or even holding the club the wrong way you are going to have a bad backhand from the very beginning. There is no way possible to have a correct backswing if you do not grip the club appropriately. It is physically impossible and you will find that you are met with countless frustration from attempting it. Sometimes even changing the position of your hands by just a fraction of an inch can provide a dramatic difference in results that you would not be able to otherwise notice.
The last major consideration when improving your backswing is that you need to pull the club back from the ball before you lift it off of the ground. Most players make the mistake of lifting the club back and up at the exact same time. This will result in you hitting the ball off centered and can greatly damage your backswing. Ensure that you are pulling the club straight back before you start lifting it up and you would notice an almost instant improvement. This is not something that should be unnatural of difficult to do. As long as you make a conscious effort to pull the club back before up, you should find that is enough of an improvement to help your backswing.