If you can get up to 200+ pushups a day, in sets of like 60-80 at a time, your tricep will be pretty good size, and toned. Dips are good too. If you want to go for looks, triceps are what fill out your sleeves.
The reason I recommend forearm curls, when you do regular bicep curls, it can hurt the forearm, but for me, it seems having stronger forearms helps keep it from hurting somewhat. With all exercises, it helps to hold the weight steadier.
Sometimes I try and do a barbell curl with 120 lbs or so, and I can curl it, but it hurts my wrists so much I have to drop it.