Fascinatingly enough most bad golfers are consistent enough with their consistent mistakes and poor play.Actually most of them ignore or are unaware of what has to be single most important aspect of golf swing. This is setup or positioning before swing.
It does not matter how good your swing is and how much correct technique you have used. If you do not pay attention to your swing, you are a bad golfer and it will clearly show when you have hit ball.
All great golfers are aware of how important setup is and you can be sure that many bad golfers are not. If you setup correctly for a shot, chances are extremely high that you will hit a good shot. So important is your setup that even if you swing poorly in a good setup position, you are bound to at least hit a reasonable shot.
A good setup will enable you achieve a good posture and sort of balance that will help you maintain balance and inevitably control throughout shot.