What are the best foods, drinks/teas, or supplements to relieve tension in your head?

Many good choices: Start with a good b complex, vit c & magnesium glycinate, citrate or taurate.Tulsi tea is great, as is valerian, skullcap, passionflower & hops.L-theanine is a good supplement, as is 5-htp. Different things work for different people so experiment, but don't forget exercise, a healthy diet rich in fruits & vegies & low in sugars, caffeine & fried foods. Practicing meditation daily usually helps a lot.