Triceps are often the afterthought for many people who work their arms. It's kind of understandable since there is no exercise more personally rewarding than watching yourself lift heavy weights in a Bicep Curl. Triceps exercises aren't as exciting as bicep exercises which are why I think people treat the muscle group as an afterthought.
Truth is, if you want to get big arms, the triceps are two-thirds of the muscle mass in there so you're going to have to work them out at least as much as your biceps.
My triceps routine is split off into two different categories. The power day where triceps are the first muscle group I exercise and the form day where they are the second group I exercise. Read this article in tandem with my How to Get Big Arms: Muscle-Building Exercise Routine for the Biceps article to get a full view of my muscle-building routine for the arms.
Coupled with the Form Day for Biceps, this is my current routine:
3 sets of heavy Triceps Cable Pressdowns/Extensions X 8 reps
3 sets of Triceps Cable Pressdowns/Extensions X 15 reps superset with Pulley Overhead Tricep Extensions X 10 reps (total of 25 reps per set)
2 sets of Reverse Triceps Cable Pressdowns/Extensions X 10 reps
1 set of Lying Dumbbell Extensions X 10 each arm
1 set of Lying Cross Face Dumbbell Extensions X 10 each arm
The heavy Cable Triceps Pressdowns are done with little attention paid to perfect form but are done with full range of motion. My goal here is size. I often cheat on the last couple of reps each set which I find okay, as long as I have good form at the start of each set. Be careful when doing this exercise on the heavy end as you may be susceptible to tennis elbow. If you get that it can last for awhile and be a real detriment to working out your arms properly. I find doing heavy Pressdowns to be beneficial to the abs as I tend to flex them hard as I am working to move the weight. If you do not have access to a machine, I recommend Lying Triceps Extensions as a replacement.
The next three sets which are supersets with the Pressdowns and Pulley Extensions are performed with lighter weight, about 60% of the weight I use for the heavy Pressdowns. Unlike the first three sets, I pay close attention to good form on these three. The next two sets are Pressdowns which are performed with the bar being held with the palm facing upward like in an arm curl. It hits a totally different area of the muscle. I like varying my grip on the bar during these two sets. Sometimes my hands are close together, sometimes they are shoulder width apart while other times I have a wide grip on the bar. I find all three grips to be effective. It depends on what I feel like going with that day.
My Form Day for the Triceps is coupled with the Power Day for Biceps, and is performed after that portion of my workout is completed. This is my current routine:
3 sets of Triceps Cable Pressdowns/Extensions X 10 reps at 85% of my power set weight
2 sets of Triceps Cable Pressdowns/Extensions X 10 reps at 75% of my power set weight
3 sets of Reverse Triceps Cable Pressdowns/Extensions X 10 reps at 60% of my power set weight
2 sets of Triceps Cable Pressdowns/Extensions X 10 reps at 60% of my power set weight
The last 5 sets are performed with varying grips between narrow, shoulder-width and wide. I suggest you change up your grip and focus on the pump and good form during these last five sets. Use a lighter weight if necessary but don't cheat.
Refer to my other workout articles if you are interested in:
More of my workout advice:
Are Bowflex SelectTech Adjustable Dumbbells suitable for you?
Should you buy Bowflex SelectTech Dumbbells in a store or online?
Why you would want to use barbells for your workouts
Why you would want to use dumbbells for your workouts
How I lost over 40 pounds in 6 months with some simple diet changes
Upper body exercises with no equipment needed
Lower body exercises with no equipment needed
Cardio exercises with no equipment needed
The Different Ways of Doing Dumbbell Bicep Curls
Inflatable Exercise Ball Exercises for Men