Where do you aim when you are looping underspin? How much arc does your loop need? Are you aware of the difference between an opening loop versus a driving loop?
Coach Samson shows a very clever way to help your students change their focal point on their aim above the net. An additional trick, you can also release the net cord and raise the net itself up to another 2 to 4 inches.
Samson uses the Nittaku Acoustic Carbon Large Grip Blade with Nittaku FastArc G1 rubber on both sides along with Nittaku 3- Star Premium 40+ balls.