What worked for me was 3 sets of standing curls,8-12 reps failing at around 10 and getting forced reps to about 12. On my final set i would get the cheat forced reps to 12 then i would quick drop the barbell, strip off 2 plates and do as many as i could, when i failed, i would strip off another 2 plates and do as many as i could, and again one final time strip off some wieght adding smaller plates if needed and do as many as i could. with no rest in between each. Decending sets. 90sec to 2 minute break in between sets.
After that I would take 2 minute break and do one set of Decending sets in the stretch position on an inclined bench. Pick three sets of dumbells and do as many curls as possible on the heaviest set, and quick drop the dumbells and pick up the one step down lighter set and finally decend to lightes set. Make sure you pick dumbell sets to put you somewhere between 8-12 rep range.
So here you have 4 total sets on bi's
I use the same principle for Tri's -- Close grip bench presses and jump into pushdowns.
I even alternate exercises for both bi's and tri's week to week giving me all around target.
I let my compound moves give my arms all the other work they need. So for me, 4 total arm sets is all i need.
My arms arn't huge, but they are huge on me, all heads are developed and visible.
Scaggs