Seated Calf Raise
Sit on a seated calf machine with your toes placed on the bottom crosspiece and your knees hooked under the crossbar. Slowly lower your heels as far towards the ground as possible and then press back up onto your toes until your calves are fully contracted and hold this position for 2 seconds. Stretch the calves between sets.

Leg Press Machine
Position yourself on a leg-press machine as you would to perform a normal leg press. Move your feet so that the balls of your feet are on the edge of the foot platform and your heels are unsupported. Remove the safety catches and keep your legs straight, knees almost locked. Keeping your heels fixed, let the weight push your toes back toward you and fully stretch the calves. At this point, press the weight back up with your toes as far as possible until your calf muscles are fully contracted. Hold this position for a moment and then slowly lower the weight back to the starting position. For variety, alternate pointing your toes inward, outward and straight forward.

Standing Calf Machine
Stand on the block at the base of a calf machine with your toes pointed straight forward. Situate your shoulders under the padded bars and then lift as high as you can on your toes. Lower yourself down slowly and allow your heels to drop as far below the platform as possible. You should feel the stretch until it almost hurts. Avoid bending your knees and do not train so heavily that you sacrifice technique.