They are always over punished more by our day to day activities. They need extra care and extra exercise. If you perform 2-3 times a week ..I think it is quite less. They need training at least 4-5 days a week. They are thick muscle covering the two bones fibula and tibia . The main muscle are gastroconamious and tibialis anterior.
The calve raises is very important exercise which should be done as the first exercise when you just enter the gym every time. 2 sets of 20-25 slow reps without weight can work great and results wonder rather than pounding huge load every time. You can use weight on the legs days only. So use calf raises as the premier warm-up exercise which pumps the blood from the calf to the heart under the huge pressure of gravity, this helps in reliving the the pooled congestion of the day if done in the evening and can be great starter for the day.
To have bigger calves it will be great to do toe raises for the anterior calve development along with calve raises. The calve raises is considered complete when the heal is raised to the maximum & you are on your toes and the heel is lowered to to maximum for complete relaxation and contraction of the muscles.