While I don't travel on overnight flights but just once or twice a year, my strategy is to sleep as late as possible on the day of the flight and "stay awake" on the flight. If I'm traveling in business/first then I want to enjoy the experience. I'm usually very tired obviously...
For more information, seeNatural Sleep Aids to Try When You Want to Avoid MedicationsandThe Best Over-the-Counter Sleeping Pills for Long-Haul Flights. Stake Your Claim on Blankets and Pillows—or Bring Your Own Andrew Makedonski/Shutterstock ...