A game changer in this regard is packing cubes or compression cubes. Usually rectangular not cube shaped but they come with a double layer of zips, one set to

A game changer in this regard is packing cubes or compression cubes. Usually rectangular not cube shaped but they come with a double layer of zips, one set to get inside the cube and another set that once the cube is full you can zip up all the way around and it will squash everything down. I fly 4-6 trips (8-12 flights) a year and never travel without them.