It is very hard to hit a tee shot straight when you pick a target ehich is 20 yards away, and you try to line up your clubface to it. Instead, step back from your tee shot, and stand right behind the ball, so that you can see right down your intended line. Find an initial target about 3 feet infront of your ball, be it a leaf, or a piece a grass. Make sure that this mark is DIRECTLY inbetween your ball and your intended target. When you make your swing, hit the ball over that mark 3 feet infront of your ball. You will find this very easy to do because the mark will always be in your perifrial vision. Your ball will travel straight towards the target.