First off,
if you arms are less than 17 in, no need to get in any specialized routine period! Use compound movements to grow ,,,,bench, deads, presses, food as some mentioned..LOL
If you can hit 17 flexed cold then start doing a more specialized arm routine. This includes heavy overhead presses, barbell curl, close grip bench, dips if the shoulders are good, preacher curls too
Aim to curl in strict form 50- 75% of body wt. So if you weigh 200lb curl at least 100lbs for reps and work it up to 150
Personally I started to see more results when I dedicated an arms day and concentrated on DB presses, heavy BB curl, Close grip bench, hammer curls.
The only thing is that this may require to take it easy on other body parts like chest, back and shoulders.