This is what i do...(using 20pound dumbell)

Biceps:

Dumbell Curls (while standing, do 20 reps, 10 each arm.)
Concentration Curl (while sitting, do 3sets of 8-10 reps.)
Hammer Curls(this focuses more on your foream though, 3sets of 12)

Triceps:

Tricep Extension(best tricep exercise IMO)(4sets of 12, or more.)
One Arm Tricep Extension(3sets of 12)
Dumbell Kickback(3sets of 12)