I am in full agreement with everything Daniel and TOO55 posted (which is usually the same on most subjects). I am going to the gym so will keep this shorter (could write about calves for hours
) but basically higher frequency, a variety of techniques, high intensity and time. Genetically my calves are terrible and I have had to force them to grow. Like every body part you have to find the best movements/execution and then just push the intensity over time. The amount of detail and little changes that has gone into my calf training is quite staggering over the years. I have been training them just on leg days recently but now it's time to increase the frequency again using a select few exercises/form and I think I can get another inch out of them
Like any body part genetics is king but because calves are stubborn for many people plus the fact they don't train them hard enough (or even at all) many have really shit calves. You even see many guys with big quads and small calves. Now the guys I know with the best calves don't even train them or if they do it's a few sets of 8-12 reps at the end of leg training. Obviously you can force anything to grow with enough effort and time but we can't discount genetics for this one. I see a guy in my gym walking out with 4pps on the squat and for very deep and great execution reps and his legs are literally half the size of mine and my legs aren't impressive
Sometimes you have to think out side of the box with weak body parts. I have done some crazy heavy weight standard/drop sets before. The thing that has given me the most results recently has been the complete opposite... very light weight and very high reps. My calves improved in lockdown from simple standing light weight calf raises with no stretch (the same can be said for cardio on tiptoes etc). Nevertheless I also think like Daniel the deep stretch is key and I would recommend unilateral reps and even using your opposite leg to do some negative reps after failure.