I have an affliction known as airplane ear (undiagnosed, but most doctors and insurance companies don't really take it seriously in my experience), which basically means that by default I am in a lot of pain when going up or down in an airplane and my head feels like it's going to explode. My parents recognized this when I was a child, and as a result we drove everywhere for trips but now I've been flying more and more as I'm no longer living in the Midwest so some places in the nation are intractable by car for me now. Unless you're Lars von Trier, you probably will need to fly at some point so hopefully this post will help people out in my situation. Obviously, I am not a doctor so talk to your doctor if you have doubts about all this; I'm just enumerating what makes flying bearable for me.
Earplanes are plugs that go in your ear that magically help your ears adjust to the pressure changes. They're sold at pretty much every convenience store in American airports. I actually used these as a kid, but I wasn't inserting them correctly which is why I was still in pain. You need to use the hand opposite to the ear in which the plug is being inserted to pull up on your ear, then insert the plug and twist a couple of times until it is snug. Yes, I know doctors do not want us to stick stuff in our ears anymore but I would rather avoid ear pain; flying is actually unbearable for me without these.
Blocked sinuses exacerbate airplane ear, so I always take a what I affectionately refer to as a drug cocktail beforehand to absolutely ensure my sinuses are as loose as possible. This drug cocktail is composed of Sudafed Sinus Extra Strength which I take about 1.5 hours before takeoff, Afrin which is a nasal spray I take right before entering the airplane, and a saline nasal spray which is a nasal spray I also take right before entering the airplane. I use generic brand versions of these to save money. This combination causes my nose to drip a ton, so I also keep tissues on hand. Again, I am not a doctor so don't do this unless you know it is safe for you.
Yes, I know they're expensive but avoiding the ear pain is worth it to me. It sucks that I will never be able to get $30 tickets to Vegas, but this is the cross I bear. I currently have flown American Airlines and Delta with no issues, and those are the ones I'm sticking to in the future. I haven't been to Europe in a long time but I assume anything affiliated with American Airlines (e.g. British Airways) will be fine. I've been told to avoid Southwest, Frontier, Spirit, and Avelo but I've never flown these.
This one is common knowledge, but it really works.
Gum helps, but ultimately the way the pressure is relieved is by swallowing. If I can't swallow fast enough to keep up with the changing pressure, the pressure will keep increasing and I start panicking especially since vigorous swallowing dries out the throat and I can't produce enough spit to keep swallowing. This is where a drink comes in handy, it allows me to keep swallowing at a higher rate.
I've been told to just take Benadryl and sleep through the flight. This is an awful idea, as I would wake up in excruciating pain. I need to be awake so I can vigorously swallow during ascent and descent to relieve the pressure. To this end, I consume an energy drink before takeoff although the extreme anxiety I feel usually keeps me awake enough. If I need to sleep, once I hit cruising altitude I set an alarm for roughly 1.5 hours before landing so I can be awake for descent.
If you're a germophobe, you can safely ignore this one. I do a strict handwashing/sanitation routine in the 2 weeks leading up to the flight, I make sure to get at least 7 hours of sleep every night, and I load on vitamin C every day in the form of either gummies or fruits. Flying while sick is uncomfortable for normal people, but extremely painful for me so I make sure I don't catch anything. I haven't flown sick since I was a child, but I don't want to reexperience that pain again.
Following these 7 tips, at best I feel no pain and at worst I have some residual pain for a day. I know it is common knowledge that you can pop your ears to equalize pressure but none of the methods in that link have ever worked for me besides swallowing. Perhaps I am not doing them right, I don't know.