I use an Aeropress Go, on multi day trips.
It's essentially a French press style coffee maker. If you use it inverted at first you can let the grounds brew for five minutes, then flip it over and press the coffee through into the cup.
It's really nice and you can experiment with different coffee styles and strengths. It all packs away really neatly as well. I freshly grind coffee at home, then fill a small nalgene bottle, which lives in the middle of the press, which in turn lives inside my mug, all relatively compact.
I generally only bother with hot drinks on multi day rides though. Even though I ride all winter no matter how cold it is, I just can't be bothered with hot drinks.