Outside-In Golf Swing?

Question:

I am going outside in so far that I almost hit my left foot. Have you ever seen anything like this? Can you give me some drills I can do to help me fix this?

Jaacob's Answer:

For a big out-to-in swing, this is a pretty cool training aid.

http://www.insideapproach.com/product_detail.jsp?product_number=1009-01

If you don't want to pay the money for it, you can stick some tall tees in the ground to the inside of the swing path right after the ball.  If you hit the tee on the through swing, you'll know you are coming to far from the outside.

Conversely, you could also stick a tee before the ball on the target line to force yourself to swing from the inside-out.  You'll have to swing from the inside to avoid hitting the tee before the ball.