Mike Burgener has a good cues to keeping a good back angle.
You probably know that you can use a stick to visualize the back angle. If it is deviating from good form (i.e. hips or shoulders rising to fast) provide feedback for the lifter by pushing him into correct position.
Cues:
- stand with our legs
- get the knees out of the way
- focus on sweeping the bar in
