Easy ways to emphasize calves include:
doing 12x10 4 days a week (you can do these with rest between sets, or as each a set between sets of other things which require rest, like bench presses) Doing 12x10 is an old Fred Hatfield trick I learned from the Ico Pro system back in 1991. Remember Fred Hatfield, Dr. Squat?
He wrote, "The calves are like your abs and/or forearms, they are used so much, there's no need to rest two days between heavy work like with chest or back."
I used to always mix it up. I sometimes would break up my 12 sets into three exercises, like seated calf raises, standing calf raises, and donkey calf raises like Arnold used to emphasize. The only thing with donkey calf raises, I didn't like the idea of having someone sitting on my lumbar, so I would do them on the leg press machine, the one with a 90 degree angle at your hip.
Mostly, though, I got my calves big from doing standing calf raises off a 5" block of wood bolted onto a metal plate at the bottom of the machine.
I would start my 12x10 with 200, then work my way up to 400 for the last few sets. After 5 months of this type of training 4 days a week, I was doing the full stack (600lbs) for the last 5x10. I would do a heavy day no less than once every 3 weeks, then back to my regular pounding of calves.
My first heavy day (after I was able to do the stack for 10 reps) was be 725 for 6. I loaded up free weights on the top bar above the shoulder harness. After 3 weeks, I got 825 for 6. Four weeks later, just before my Air Force Traing was over, I loaded the machine up with 1005lbs and got 6 reps in front of about 20 people. It was awesome. After leaving training, the new gym I had didn't have this old-type of standing calf machine so I drifted away from the exercise.
A few years later I tore a tendon (playing volleyball and landing on someone's foot) so the ol' days of massive calf raises were over, but the damage was done, of the 12x10 that is, and eventually my calves got up to 19". These heavy sets build up over time, but the thing is, most people don't do enough volume for calves to even stimulate exercise, let alone generate size.
