If you're planning to use a decongestant, test that it works for you ahead of flying.

Because the US gov't has made pseudoephedrine more difficult to buy, many allergy or cold medicines use phenylephine instead. If you *don't* have to show your ID and sign a guestbook when buying your allergy medicine, then you've bought phenylephine.

The problem is that it doesn't work well for some people. I found this out myself-- luckily just on the ground-- when I bought a phenylephine-mix cold medicine. That led to one night's lost sleep, because my sinuses stayed as bad as if I'd taken nothing at all. As soon as I took a pseudoephedrine my sinuses became tolerable.

You wouldn't want to find out if it works or not during the descent.

I've also had the horrid experience of developing a clogged ear because of a cold during a flight. The best solution for that- along with a decongestant- is to continuously sip water until it lands. I drank well over a liter of water for that. I'd always try to carry water for flights before that, but after that I would double check.

That was before the water ban: I can't imagine how my eardrum would have survived with today's rules. Imagine having to beg for several cups of water in order to fill your empty water bottle (this was in a country that today bans bringing water on board, even after security).