I alternate every week between seated alternate dumbbell curls and seated alternate hammer curls. I pyramid up to 100s on both. My sets typically look like this:
30s x14-16
50s x10-14
70s x8-10
100s x4-6
The 100s involve some momentum, but it's still very controlled and I do the negatives nice and slowly. Naturals simply aren't going to get great arms curling 40s and 50s for 8-12 reps week in, week out. They need to be demolished, pyramid style.
I'm away at school, and my school gym's dumbbells only go up to 80s, so I've been finishing my last set with 80s for 8-10 reps. I'll be home for spring break first week of April where I will have 100s and I'll get my brother to film me, because it's probably pretty worthless saying you can curl 100s without a video to back it up.