Throwing spare parts into a backpack or purse is a recipe for lost or damaged gear. A loose mouthpiece will collect lint and pocket fuzz. A cartridge might leak if it's jostled around. And you'll inevitably lose that tiny o-ring that keeps everything sealed.

Keep spare parts in small zip-top bags or in the dedicated compartments of your case. Label them if you have different types. You'll thank yourself later when you're not digging through your bag at the airport.