To get started, you’ll only really need a few things, some of which you might already have on hand.

Thermos: in theory, any thermos will do. In practice, I have the best luck with thermoses that have an insulated lid, like this food jar from Hydro Flask. In cold weather it matters less and most any decent thermos will work, but it makes a massive different for cocktailing in warmer weather or over the course of a couple days. With a little careful planning, I still had ice into day three of a backpacking trip almost solely because of the hydro flask food jar.

Measuring & Prep: I prefer to use the Leopold-style jiggers from cocktail kingdom over other options, but this little doohickey from OXO is accessible, cheap, and lightweight.

Mixing devices, juice presses and strainers: I use the Hydro Flask food jar as both a mixing glass and a shaker tin, and for outdoor cocktailing, dual function ice-storage/mixing vessel is pretty delightful. A hand citrus press is the way to go at home, but I’d advocate for the use of a handheld reamer when cocktailing abroad. I don’t use a mixing spoon when outdoors, instead rolling the thermos between my hands to somewhat simulate a mixing spoon. Strainer-wise, I prefer a hawthorne strainer like this one for the sake of simplicity. When a little more pressed to cut down on weight, I’ll just pour from the thermos very carefully and just deal with the ice shards.

Flasks: for ingredients or finished cocktails. Instead of carrying an entire bottle, I’ll sometimes premix the cocktail, or at least just carry a small amount of the ingredient.

Serving: you don’t need to be a total dweeb and carry glassware. An enameled camping mug will certainly do, or a hard-wearing hydroflask rocks “glass.”