Triceps extensions typically provide maximum overload when your forearms are parallel to the floor. However, performing them on a slight incline with cable resistance keeps constant tension on the triceps throughout the entire range of motion.
This setup is especially effective because the cable increases resistance in the contracted position—something most free-weight variations lack. Be sure to pause for a second or two at full extension to really emphasize that peak contraction.
One challenge with this variation is getting into the start position, especially without a training partner. A simple workaround is to use a resistance band or tube to get into position safely, as demonstrated in the video.
Give it a shot and feel the difference in your triceps training!