I do 4 sets of 20-25 heavy . On the leg press and seated calf machine. I also hit my anterior tibialis with burn outs. I at least do these 2 x a week. I hope this helps
They're the same as other muscle groups, albeit a little stubborn. Hit them often, with a high load, and in a stretched position. By this I mean do them off of a block.
Donkey calf raises can be a good addition as well.