Calf raises (machine):
Put your socks on the machine platform and shoulder its rollers. Lower your heels and then slowly raise them. Perform the desired number of repetitions.
You may use different machines for this exercise: Hack machine, Smith machine, etc.
Mistakes and Recommendations:
The number of repetitions and sets depends on your goal. You may perform 12-15 repetitions in 3-4 sets. At the point of maximum effort, pause for 1-2 seconds. If your goal is fat loss, you may perform 20-30 repetitions in 3-4 sets.
You can also put a pancake or a step under your feet. It will increase the amplitude of the movement.
Do not forget about pre-stretching and warming up your muscles.