Earplugs. Put them in as soon as you scan your boarding pass and are waiting in the jetway to get on the plane. Nothing that is said to you after that point will be important until you're off the plane; and if it is, you can just take out one earplug and say "say again?" You can avoid most of the annoyance of in-flight announcements and advertisements, screaming babies, and jet engines.
Drugstores. Your destination probably has them. You don't need to pack any toiletries that you can easily obtain in one. If you are flying to New York City, you do not need to bring toothpaste with you; they have toothpaste in New York City, and you can just buy it in the Duane Reade shop that's a block from your hotel. They have toothpaste in San Juan and Paris too. In any tropical destination, they have sunscreen there — and the sunscreen they sell there is actually safe for the coral reefs.
Water bottles. Many major airports have stations for refilling water bottles after you clear security. You can take an empty water bottle, fill it up, and carry it on the airplane.
Masks. In the old days before COVID, nobody wore masks in airports, and lots of people got colds or flu when traveling. These days, you can wear a mask and people may think you're weird but you are less likely to pick up random respiratory diseases. I regularly wear a standard 3M N95 mask in American airports and no longer get the sniffles every time I travel.
I disagree with the toiletries thing. It’s no panic if you forget them, but straight after a long haul flight, you want to refresh which includes brushing teeth.
If you’re flying somewhere hot, you want to apply sunscreen and get straight in the pool at your destination. It really makes it feel like the holiday is started,
Don’t forget that sunscreen can be expensive depending on your destination. Going to a family or friends house and the beach? NBD. Flying to Cancun and into a resort? That on prem sunscreen is gonna cost ya mucho dinero compared to BYO.
There's an additional reason why masks are popular in Asian countries: During flight, in-cabin air tends to get quite dry and that can easily upset your throat.
A mask reduces the humidity loss caused by the dry air exchange.
The mask thing is not a joke. My cousin came to visit and the moron didn't get the 2023 vaccination. Came over, and spend 80% of thanksgiving struggling with covid.
300 people in a crowded plane... Circulating the same air, what do you think was going to happen?