I'm not a flight attendant, so it's not a big deal, but I never have trouble flying anymore.
I always treat myself with Sudafed throughout a period that starts 24 hours before a flight through 24 hours after the flight.

I use Flonase every single day so that my ears don't feel as full as they otherwise would. Flonase, however, won't help for a quick boost.
If I get on a flight while I feel more congested than usual, I also treat myself with something containing oxymetazoline like Afrin.

That helps.

My ENT has mentioned different treatments such as the balloon thing, but I usually manage okay with what I've listed above.
Of course, I'm not a flight attendant.