Member Australian PGA, Former Club Professional
Surfers Paradise Golf Club
In my 30 years experience as a golf professional one of the most common faults I seen the average golfer make is that they don't know how to set up correctly.
A lot of players think they have to aim their body at the target and forget where their club face and feet are pointing.
The best thing to think of for a correct set up is to picture yourself standing on the nearest track of a railway line to hit a golf ball sitting on the other track.
Your feet, hips and shoulders don't aim at the target they aim parallel but to the left of the target. The only thing that aims at the target is your club face on the other line.
Such a set-up encourages swinging the club face through the ball along - rather than across - the target line. Try it you will soon see your shots fly straighter.