You work on a machine to learn how to do this and it works particularly well in children and in patients who don't want to take medications. Certainly extremes of heat are triggers of migraine, particularly in kids who play sports outside for hours at a time. Good hydration and being aware of the heat is very important. Air conditioning can also provoke migraine but less commonly. Whatever feels good to you.
Different people do different things.
There are meditative tapes. It's particularly used to find the thing that works for you. It certainly means your headache isn't that bad. I've never heard of sex as a remedy, but there are people who gets coital migraines and there are drugs for that. They're called exertion headaches or coital headaches.