We took colouring books and a big sticker book, we let our daughter stick the stickers all over her book and plain paper to make designs, also some new books to read to them and something they can play with, I also let my daughter have my phone to take pictures. The flight attendants also let her hand out the sweets lol. Good luck with the flight

I spy. Puzzle books, colouring in books, reading books. Card games are good, so many different games you can play with one pack of cards

Pack a backpack with colouring, playing cards (UNO is a great game!) books etc. Also talk to the airline stewards. They can help as many airlines have kids activity packs on board. Also try to encourage sleeping by buying a fun neck pillow and eye cover. Depending on the child’s age you can get special inflatable pillows that allow them to lie flat on the airline seat. I think one brand is Plane Pal but I’m not 100% sure.
Good luck!

Surprise the child with a new toy to occupy themselves with. Books are great and keep plenty of snacks on hand.

You can get up and do regular walks up the aisles. You can make a game out of it by getting them to look for someone in a red shirt and then someone wearing yellow etc. Otherwise it’s unfortunately mostly sitting activities like reading, coloring etc.