Having big, strong, toned biceps is cool and all, but they won't do much to have your arms stretching the seams of your sleeves. You're going to want to work on building the back of your arms, your triceps.
Tricep Anatomy
Not to get into too much detail here with anatomy, but in order to make the most of your tricep exercises, it's important to note that there are 3 heads of the triceps (hence tri). You have the long head, the lateral head, and the medial head. While all three work to extend the elbow, the long head also crosses the shoulder joint and attaches to your shoulder blade.
In order to make your tricep workouts the most effective, you're going to have to use a combination of movements to hit all three, not just one specific head, and use each one through its full range of motion, so your basic press-downs, while effective will only hit a fraction of what you want.
That horseshoe shape you might be aiming for on your triceps? That's the lateral head right there.
You may feel like you get a lot of tricep focus doing your other pressing exercises like push-ups or chest presses, but adding in some of these isolation exercises will go a long way to building the strength and size you want from your arms.
Incline Chest Supported Tricep Kickback
The key to this exercise is controlling the movement, pausing for the contraction at the top, and avoiding any swinging motion.
While you won't necessarily get that pump or burn feeling from these like you would other tricep exercises, you will be feeling them later.
Rolling Tricep Press
Like we mentioned earlier in our anatomy section, the long head crosses over the shoulder joint, so in order to effectively train that head, we need to include exercises that involve the shoulder joint.
"Katana" Tricep Extensions
If you want to do your best Deadpool impression, or just want to crush your triceps, give these extensions a go. You're going to get a big stretch at the bottom of the movement and a strong tricep burn at the top.
I will say that do these if you have good shoulder mobility in order to get over the head. If you don't, no worries, there are other options to get those same tricep gains.
Band Crossover Tricep Extension
We're rolling into an exercise that kind of looks like a press-down, but you are also incorporating some extension at the shoulder to target that elusive long head. This makes it more effective as you're hitting all three heads.
Band Tricep Kickback
This is my favorite burner exercise to hit the triceps. We're getting constant resistance from the band during these as opposed to your usual dumbbell kickbacks, where the resistance really peaks at the top of the movement.
How Many Reps?
This is the most common question. How many reps should I do and the answer is that you should be hitting all kinds of rep ranges. Some exercises I will take in that 8-12 range and make them heavy enough that I couldn't do more than 15.
Other exercises can go in that 15-20 range for some added burn. And if you really want to burn your arms out at the end of workout, go for 20+, especially on those band kickbacks.