Common problem encountered while learning how to spray, (these are from my own experiences)
confidence and speed – if you do not have enough speed when stopping, the force you lay down on the ice will barely be enough to spray at all.
Weight – if your feet are in the wrong position the weight will be unbalanced which again will not be enough to spray as there is no momentum pushing the ice up/ no power to push a large amount of ice forward.
Angle – if the angle of your skates is wrong the weight and speed you put into your skating and hockey stopping will be useless as you need the edge of the blade to life the ice up in the air and the power/speed and weight to push a large amount of ice forward aka a good spray.
The better the angle, the better the life (more ice will come up),
more power = more ice as there is a increase of the amount force scraping the ice off the ground