My preferred way for making coffee on tour is a Melita coffee cone with a cloth cone filter. The cone can clip to the outside of a bag (using a carabeaner), and when you finish brewing the coffee you can dump the grounds and rinse the filter. The cones are cheap, I think I paid $4 for mine and the filter about the same.

I really like making coffee with a Moka Pot (stovetop espresso maker). I even have the GSI camping version that needs a mug to "catch" the coffee, in lieu of the typical reservoir. It takes up less space in the bag, but even then, I feel like it takes up too much space. So I save it for short out-and-back tours.