Several months ago, San Jose Sharks strength coach Mike Potenza posted the following videos to demonstrate corrections for several hip extension exercises on HockeyStrengthandConditioning.com.
The purpose behind these exercises are to facilitate corrections for those who may be demonstrating too much hip external rotation when performing said exercises. As you can see, he first demonstrates the faulty pattern, then follows this up with the corrective strategy.
Commonly, we will also see individuals who may not be ready to perform the single leg straight leg deadlift and therefore, I will often regress them to the hip airplane exercise as suggested by Stuart McGill. The emphasis here is on the closed chain internal rotation / adduction portion of the exercise so a cue I normally use is to tell the individual to "close the book."
It is also not uncommon for individuals to have difficulties when performing this movement for the first time. Therefore, here are a few reactive neuromuscular training techniques to help facilitate proper hip control. Please remember that a restricted posterior hip capsule may limit the available range of internal rotation.