Ahh, I see. Well, when I do direct bicep work these days, I will do it DC style of course and do a warm-up set of 10-15 reps with a moderate weight, and then I go heavy as I can to do 10-12 reps. That may be like 80 lbs x 15 and then 110 x 10 for example. Same with any of the other exercises. Before that when I did more volume, I would do a warm-up set, and then two sets of 8-10 with 85%-95% of my maximum weight. I would keep doing this each time curls came up until I could do 10 comfortably upon which I'd increase the weight the next time and repeat the process.
The only other exercise I used besides curling was inclined dumbells or preacher bench because of the excellent stretch you get at the bottom of the motion.