If your ball striking is inconsistent, focus on your balance throughout the swing. Balance is one of the most important aspects of being a good ball striker, as the ultimate goal is to return the club back to the starting position at impact. Therefore, if your weight is falling towards your heels/toes, the club will be unable to return to the correct impact position consistently.
If you watch professionals swing the club, you will virtually never see a time where they are out of balance in the swing. Conversely, go to a public driving and watch your average golfers. It is a safe bet that poor balance will be a fairly consistent theme.