The primary thing w/ bis & tris is getting a good contraction of the muscle w/ full ROM. I've got throbbing tendonitis in both wrists, forearms & elbows. 10 yrs ago I was doign 45 lb DB curls, and these days I can't handle more the 30-35. My "genetic gift" is my bi peaks but conversely, my triceps suck (and look that much smaller because of my better biceps).
I tend to do bis after back & tris after chest - i.e. its already being worked , so I don't need to do a lot of accessory work specific to those muscle groups. My workouts consist of:
Bis:
super of ezbar curls (for same reason as above w/ straight bars) + DB hammer curls - the angle doesn't hurt as much as std curls
-- for ezbar curls, if I can't go heavy, I can increase volume with something like 21's instead of heavier full ROM sets.
seated full ROM DB curls - because it hurts, at least seated I can hold elbows close and focus more on the ROM than the weight.
Tris:
- tri dips or skull crushers + close grip press if I can handle the pain.
If not:
- super - cable tri pressdowns + cable OH tri extensions
---- here again, if you can't go heavy, you can do the full extension, hold it for a count and do a slow negative (i.e. time under tension aka TUT is the focus vs flapping out heavy sets)
DB kickbacks, again focusing on the extension.