Car camping I take fresh ground grinds for a coffee press and half n half. Still use the jetboil.
For backpacking Starbucks instant because I hate dealing with coffee grinds. I don't like the way they fill when wet. Odd I know but if ya all haven't figured it out yet I am odd. But my new favorite trick is to use Bourbon cream in place of half n half. Yummmmmy. Only time I flavor my coffee.
Usually Starbucks Via but a couple months ago we tried Gastro Nome Instant Coffee pouches. The coffee pouches dissolve so you don't end up with any packets to dispose of. Coffee flavor was pretty good but the pouches didn't 100% completely dissolve and left a bit of white residue in the mug. Probably go back to Vias.
I like to bring along some instant coffee for afternoons or in a hurry. The Medaglia D'Oro espresso mix or Nescafe Classico are great -- both easily available in the grocery store, and extremely cheap compared to stuff like starbucks via. And probably taste better.
But if we're not going anywhere in a rush in the morning, then there's no reason not to have real coffee. For years I've been using a little strainer like the one shown here, I had to cut off one of the wings to get it to fit nicely into my mug. I bring a ziplock baggie of ground coffee and do sort of a pourover. It's a great cup of coffee and not a big hassle. It's easy to get it clean enough by banging it on a rock, then I throw it in the dishwasher when I get home.
I keep waiting and hoping someone will invent a coffee-sicle that you can just suck on as you go down the trail. Something frozen would be hard to do, but one kind of like the freeze-dried ice cream you can get for backpacking might work. It rehydrates as you suck on it. Make the stick something marmots like so no waste involved. Suck it up, Buttercup. You could have different coffee flavors - circus peanut, recycled filter, Jack Mo, gas station, etc.
For anyone who wants instant packets that are creamer & sugar flavored:
At home, my husband likes Coffee Mate French Vanilla, and Starbucks Via used to have vanilla flavored packets that he liked when camping. But they discontinued those. He started using these Vinacafe ones and thinks they're good enough.