I had to negate BB curls altogether because they sucked in so many ways - not feeling them in biceps, DOMINATED my wrists, just not a very good exercise for me.
I can't say at this point there's any body part I have a tough time isolating. Those "double pop" (or pump) are definitely great techniques to do with both of these.
In addition, when working calves, I believe those who have tough time making them grow need to approach them two different ways. First, do DC-calf training. Pick a weight that you can only complete 12 reps with; hold the contraction for 5 seconds, then fully stretch your calves for 15 seconds. Rinse, repeat. Much harder than it sounds, though... and these are generally best done with seated/standing raises.
Then, you should start doing your high-rep foo-foo work. Why I call this "foo-foo" work is because I see a million guys who go into the gym, load up a calf machine with about as much weight as possible, and these interesting little knee bounces, it looks like. Even guys with great physiques seem to train their calves like dumbasses sometimes. These should be with moderate-heavy weight, but make sure you're still forcing the contraction and lifting with control - but these shouldn't be as heavy as the DC training.
Also, for whatever it's worth, in the second exercise I feel like it's integral to try focusing on the soleus throughout. People will tell this is bullshit and they're wrong, it can be done.