I think the best drill is the Gate Drill
Michael Camastro of Michael Camastro Golf Academy at Broken Arrow Golf Club writes:
"I am a huge fan of Eyeline Golf. Your products have been a big success in my teaching. I think the best is the gate drill... all my students spend hours using this drill which has proven great results. You guys are the best keep it up!"
Thanks Michael! We have several products to help you set up the Gate Drill. Here are a couple examples:
Create a Stroke Path Model with Tees by Zach Johnson
Create the Gate Drill with the Putting Impact Putting System