I've gone with the high volume as fast as possible approach to spark new life into my calves and seems to work pretty well. The calves get a workout all day long as we walk completing our normal day to day activities. So instead of hitting them with a few exercises of 10-15 rep range why not blast them into submission as heavy and as fast as possible.

So here is what I've done that I have found that works for me.
The idea here is to do 100 reps of calf raises straight with minimal rest.
On standing calf raises select a weight that you can only get 20 reps for and no more if I can get 21 it's too light. Once you know what that is your off to the races.

Perform 20 reps with your selected weight and right as you fail there step off and count 10 seconds and continue your calf raises doing as many as you can until you can't complete a clean rep. Then take another 10 second break and continue your calf raises until you get to 100 reps. Again only take a 10 second break when you fail. The goal is to get to 100 reps with that selected weight with minimal rest.
The first week you do these your calves will be screaming. Then once you get into it you can complete this routine twice a week.

Then I'll go back to the norm for a little while using a couple different exercises and multiple sets.

I've also done a variation to this where I select a weight and do 10 reps with my toes pointing IN, then immediately do 10 reps with my toes pointing OUT, and then immediately dov10 reps with my toes STRAIGHT. I'll take a 20 second break and do it again completing 4 total sets of these and then add on a 50 reps straight with my 10 second pauses. This is another one I like to throw in when I want to shock my calves and spark some new life.

Be warned it will have you walking funny when you try these for the first time. But you'll love these routines and you'll notice it does work. Seems like your not doing much cause you could have these done in about 5 minutes but for the next several days after this routine you realize it was plenty.