Record a stereo track, pop the cassette into my stereo system player, another cassette in the boombox.
That's where I started, too. I had Alesis HR16 drum machine and MMT8 hardware MIDI sequencer and a small mixer, so the first track was drums and maybe synths and either bass or guitar. I really had to think about how what I was recording now would end up sounding along with all the stuff I was going to add later, and after all the generation loss. I also had to learn how to know what I was looking for, get it, and commit to it cause there was nothing to be done later.
Then I got a Fostex X18 4 track, a different mixer, and some things like a compressor and effects and some consumer graphic EQs. I would stripe track 4 for FSK sync for the drum machine and sequencer and then had 3 more tracks to record to.
Started messing with Cakewalk on Windows for Workgroups, and followed the upgrade path. Eventually dumped the hardware sequencer and drum machine and would just sync the computer via SMPTE to Cakewalk.
Cakewalk Pro Audio (v4) came out, but the machines back then made it impractical for most things. I was messing with it and SoundForge, but still doing most of my actual audio tracking and mixing in analog.
Eventually upgraded to ADAT (still synced to the computer), then two ADATs synced to each other and the computer. The mixers got bigger - a Tascam 1624 then a Soundcraft Ghost. The outboard rack grew to 7 feet tall...
Then I switched to Mac and Cubase, then Opcode Vision, and was able to do a bit more ITB production.
Then back to PC and Cubase, then Sonar, and finally the computers were able to do most of the things that I'd been wanting them to do since 1995 and I sold most of my outboard and moved to all ITB around the time I was turned on to Reaper, and I have never been as happy with these things as I am now.