check in online if you can, as this can be done in advance. Print copies of your boarding passes, as it’s much easier for getting through security, if you have to scan them the passes.
take a cross shoulder bag for your passports, money and tickets, to keep your hands free. a back pack can be used for the rest of your stuff.
Hoodies or light jackets for the plane, as the plane can be cold.
bring an empty water bottle to fill up past security for the plane. you can buy food/drink past security, but it can be expensive. we buy supermarket meal deals for the plane (use the drinks before hand).
plan your travel and allow plenty of time for delays - it’s not only the time it takes to get to the airport, it’s getting to the checking desk, queuing for bag drop offs, getting through security and finding your way to the boarding gate.
go to the loo before going to the boarding gate - providing head to the gate once it’s announced, you’ll have plenty of time. better for you all to go before getting on the plane.
check what you can and can’t take in hand luggage and pack accordingly, so you don’t have to leave anything at security.
as you go through security, you may have to take your electricals(phone, tablets etc) out of our bag for scanning, so it’s worth keeping them easily accessible until you get through security.