There are many things that can go wrong with a swing, and you can spend a fortune on teaching aids designed to fix them. However, you can fix many swing problems with nothing more than an empty box. You can use one in a variety of ways, depending on what kind of box you have available.
Fix a Pulled Shot
Shoe boxes are convenient tools for correcting swing path errors. Many players struggle with out-to-in or over-the-top swing path problems. For right-handers these result in pulled shots (shots that start left and stay left) or pull-slices (shots that start left then curve right). Take a shoebox to the practice range and place its front edge about 6 inches behind the back of the ball and just outside of your target line. If you swing down the line or from in-to-out, you'll miss the box and hit the ball. If you swing from out-to-in, you'll hit the box instead of the ball.
Fix a Pushed Shot
Pushed shots are a similar problem, except the swing path travels from inside to outside. For right-handers the shot starts right and stays right, or starts right and hooks back to the left. This time, place the shoebox's back edge about 6 inches in front of the ball and just outside of your target line. If you swing down the line or from out-to-in, you'll hit the ball and miss the box. If you swing from in-to-out, you'll hit the ball and the box.
Fix a Fat Chip
If you hit behind the ball when you chip, your angle of approach with the club isn't steep enough. By placing a standard flat golf ball box about one grip length behind the ball, you can fix this problem quickly. If you don't hit down on the ball, you'll hit the box on your downswing. To miss the box, you'll have to make a steeper downswing and hit down on the ball.
Fix a Crooked Putting Stroke
Most putting aids are designed for a specific kind of putting stroke. If you putt on an arc, you need a different putting guide than if you take the putter straight back and through. An empty golf ball box can work for either style. Most ball boxes are thin, typically four balls long by three balls wide. For a straight stroke, simply use the top and bottom of the box separately. Hold your putter behind the ball and place the box halves on each side of the ball, slightly wider than the putter head. Start with the boxes about 1 inch outside the putter's toe and heel, then gradually move them closer together as your putting improves. For an arc stroke, you only need one box about an inch outside the toe. Move the box closer to the toe as you improve.