I will include some things I think were useful for me.
Now a days you can check-in to your flight 24 hours before the flight time. Do this. It may help you choose the seat you want (if not yet chosen) and way easier.
People with smart phones (most people now) use apps like Apple wallet or equivalent and add your boarding pass in the wallet. Very helpful.
While booking flight tickets, try to see if you can join any rewards program the airlines is offering. It doesn’t hurt to add some rewards no matter you use them or not. I usually check for cheaper flights in any compiled website like Booking buddy, Kayak or Expedia, compare prices and see which i can get cheaper. Then I will login to that specific airlines to add to my rewards.
Please do not stand up as soon as the flight lands. No one will kidnap you or steal your belongings. It anyway takes time for them to let you out. So even if you have a connection, you cannot jump off the flight unless you can start walking out. You will have plenty of time.
If you miss your connection, the airlines will try to find another of their flight. But if they couldn’t do it on the same day and you had to book a flight on your own, be sure to ask for a credit of the tickets of the current airlines. They do that.
As big bottles of shampoo, body wash or conditioners are not allowed over 100 ml but you are going on a 10 days vacation, you can buy these shampoo, conditioner bars. While I was a kid, we used only soap bars instead of body wash bottles. Also you can help the environment by avoid using plastic bottles.
If possible carry your food in any of those bio-degradable disposable boxes while you leave home to the airport. You can pack healthy and save money from buying food from the airport.
I always carry a set of clothes including socks and under garments in my carry-on (even if i m checking in any luggage). This helps me a lot if my luggage is delayed or lost.
Always wear your heaviest shoes to the flight. You will have more space to pack other type of shoes in the bags
If it is a long flight, sleep as much as possible. You will not feel jet-lagged.
Send your itinerary to your close friends and family if you are travelling long distances (international). They can contact you and know where you would be at any time.
If you are not using your phone to listen to music, podcasts, or watch movies just keep it in airplane mode or switch it off. Save battery.
I started carrying a hydrating face serum because I have a dry skin and flight makes my skin much drier. They are usually under 100 ml.
Carry facial wet tissues. Very helpful.
Sometimes I carry these wet face masks. Removing stress from the face. You will never have a flight face (Long flights specifically).
Usually Cabs/ Uber from the airport directly could be very expensive. You can wait to take a shuttle bus to some spots where you can rent cars and then from there walk to the roads nearby to call an uber.Of course this is much more easy if you have less luggage to carry and also not in a hurry to get somewhere