What are some of the best ways to treat rebound headaches and migraines while they are happening?

Aspirin and sleep: Rebound headaches implies that you have been using excessive medications and have become resistant. I have found that many forget how effective Aspirin alone can be. Sleep is the single most important treatment for migraine. Sleep agents such as Benadryl and anti-nausea agents such as Reglan (metoclopramide) are helpful. Lying down in a dark and quiet room works best.