If compression socks are a little too much for you, you can do some in-seat exercises to get the same effect. Airlines such as Qantas and Virgin even suggest exercises, and Qantas suggests engaging in them for three or four minutes every hour.

Exercises include lifting your feet off the ground by a few inches and rotating them in circles; keeping your heels on the floor and pointing your toes up as far as you can, then pointing your toes down while lifting your heels up; and rolling your shoulders forward and backward.