I did it once for seated calves, then a few days later again for standing. Its really simple, you pick a weight that you can get 20 reps on. When you get to 20 reps/failure, you rack the weight. You then rest a very minimal rest, 10-15 seconds, and go again to failure. You do this until your rep total reaches 75 reps.
I have to say that my calves have never been this sore before, and the routine was about 4-5 minutes total. I'm going to stick with this for a while, but use progressive resistance, adding weight to it every week