my arm workout usually looks like this. But I can sometimes seem like I'm just running a muck in the gym because I'll get into one of those "zones" where I start lifting in very high volume and just try to keep the pump going until I feel like I've had enough. But anyway,this is what my brother and I did yesterday.
Started with a set of standing alternate dumbell curls
1 warmup set 30lb dumbells 15 reps (1 set only)
Then moved to big bar curls holding the bar at slightly wider than shoulder width apart so the entire bicep is incorporated
6-8 reps with 135lbs
8 reps with 115
10 reps with 95
Next was seated hammer curls
6-8 reps with 80lb dus (they don't seem so heavy after watching your training partner do them with 150's)
8 reps with 65lb db's
8-10 reps with 50lb db's
Then dumbell preacher curls on the incline bench
8 reps with 50's
8 reps with 40's
and another 8 reps with 40's
Like I said,sometimes I'm less organized and tend to do twice that much volume. But this is a pretty average arm routine for me. I always go heavier when I'm training with my brother. we push eachother in a way that only two competative siblings can. He's a little bigger,a little stronger but we are pretty equal when it comes to bi's and tri's. I have more muscular arms. He's got an upper torse like a bull.