Yeah, coffee bags is the easiest, lightest and least faff that I’ve found.
As above, strongest ones you can get (I think Taylor’s java are reasonable) and double bag. Coffee mate if you want.
Do it on some kind of jetboil type thing. I like oex heiro to do enough boiling water for 1 person general use.
If you are properly remote or want to carry less water weight, or want to enjoy the general terroir of where you happen to be, then some kind of water filter is useful too