I call this drill the gate drill! The idea is to simply swing through the gates! One of the main swing faults I see from a day to day basis is a poor swing path which most often is from the outside to in type motion during the downswing. A great way to fix that path is to simply set up two golf balls, tees or tennis balls with one on the outside of the ball and behind the ball. Th other on the inside and slightly ahead of the ball.
Next just tee up a ball in between the two gates and hit the ball in the middle swinging at slower speeds. This will improve your swing path over time and give you a better chance for more distance and improved accuracy! View the attached video of me performing this drill!
PGA Director of Instruction