If you are flying and aim to travel (relatively) light, buying a bag or suitcase designed as carry-on luggage, which can be put into overhead lockers, is a bit of a no-brainer.
Aerolite sells a whole range and its website lets you shop by airline and maximum cabin-size allowance. For example, it sells a £49.99 expandable case (55 x 40 x 20cm), suitable for Ryanair priority boarding and Tui flights.
