Checkout this video of Cameron crushing Triceps Extension, this can be done with an arm workout day. This workout can also be used on days when you are doing Shoulders or Chest. Always make sure you hit the big main muscle like Chest before going into the smaller muscle like Triceps or Biceps.
Typically this can be done for 4 sets the lighter weight being the heavy set and then dropping down. Pyramid action, the lower higher reps at the bottom to the lesser sets at the top with heavier weight. Include some actions like triceps rope extensions, skull crushers, single arm triceps extensions to really set this off. All of those can be done in a pyramid system also.