Don't Forget the Lengthened Position
Most multi-joint pushing exercises also involve a contribution from the triceps. However, these exercises predominantly train the triceps in their mid to shorten-range position. This is why you need to include focused elbow extension exercises that place the most mechanical tension of the triceps in the lengthened range.
Exercises that do this include overhead dumbbell triceps extensions or overhead rope triceps extensions (shown here).
For the overhead rope triceps extensions, the cable (the force vector) should be positioned at or below shoulder height and performed with a forward torso lean to maximize the tension in the stretched range.