I use Audacity (free) and a $50 Blue Snowball condenser to record from a close-mic'ed Katana amp isolated in a closet. I don't do anything direct, which is probably dumb but oh well. My setup lets me multitrack by playing back through monitor speakers on my desktop-- the amp is loud enough that I can hear it fine without having to mess with real-time playback/playthrough.
Same setup for acoustic guitar, but I move the laptop and mic to the master bedroom closet upstairs and just play with the sound hole close to the mic.
I have never tried recording vocals. Maybe next year.
Audacity has a lot of mixing and mastering stuff built in, but I don't really know how to mix or do any of that producer shit so I just guess. I'm just lucky when I get the levels right and everything sounds relatively equal/appropriate.
So my shit is totally bargain basement, but the end result is what I consider decent lo-fi. It may sound like shit to someone with better ears than mine, and/or someone who understands mixing, but to me it's effective enough to produce multi-track song stems I can share.