Keep it simple, heavy compound exercises will build big guns, stay away from machines and pussy "shaping" exercises
Bis - standing barbell or dumbell curls, incline dumbell curls, preacher curls
Tris - close grip bench, weighted dips, skull crushers, overhead
extensions with 1 dumbell or ez curl bar
My arms were 12" when I started, they're around 18 1/2 cold now, it does work