HOW: Begin in a seated position with your toes resting on a slightly elevated surface with some form of padding resting on your knee and a weight resting on that padded surface. From here, you are going to quickly push up onto your toes working to improve your elastic recoil.
FEEL: You should feel your calf muscles working as you quickly push your toes down into that elevated surface.
COMPENSATION: Avoid having the motion come from your hip, instead make your ankle work through a range of plantarflexion by pushing your toes down into the elevated surface.