Let's say that lifter X has:
A) A 1200 pound 3 lift total (300 bench, 400 squat, 500 deadlift).
B) Uses some bicep work, but not a lot.
C) Has decent sized arms, but wants bigger.
First they need to realize that the bicep is a small muscle. Triceps make up 2/3rds of the arm (in general), so big arms are build by working both biceps and triceps. With that said, here are some suggestions.
1) Rest Pause
. Focus on not only building strength on curls and bicep exercises, but also on limiting rest between sets. This combination is brutal. Workouts are brief but potent.
I recommend either 5 or 7 sets per bicep exercise. Sounds like a lot but it isn't. These sets function like one big set with minimal rest.
: Use the same weight for every set. You do not want to be playing with weight when rest is limited.
For the 5 set rest pause I have used 30 seconds of rest in between each set, or 10-15 deep breaths. When you can perform 25-30 TOTAL reps for all 5 sets, add weight the nest time in the gym.
For the 7 set rest pause I generally use the following rest scheme:
30, 30, 60, 60, 90, 120 seconds
When you reach 35 to 40 total reps for the 7 sets, add weight the next time in the gym.
2) Volume week
. Once every 3 to 4 weeks hammer the heck out of biceps with 10 rep set after 10 rep set of curls. Just head into the gym and 10 rep set yourself for a complete hour. Plan a few days off after this, as you won't be able to touch your nose. Eat big, big, big, and sleep bigger.
Don't do this too frequently, but every now and then a "nuke" day is good for the soul.
3) Go simple
and focus on getting your barbell and dumbbell curls crazy strong. Do 3 sets or each twice a week. Dedicate a year to seeing how much you can improve these lifts.
Just 3 ideas that came to mind. Might work, might not. Try them.