I've made some maps back in the day. The first editor I used was Lode Runner built-in editor for ZX Spectrum. Once I got PC it was Wolfenstein 3D and few other games. Making maps for Doom and Heretic was cumbersome until a better crop of editors appeared like WadAuthor. Then it was Duke3D and I used to know Build editor pretty well, I spent years making stuff for DN3D long after the next generation of FPS games. Dabbled a bit in making maps for Descent II when I discovered that second CD had a full fledged map editor. Obviously I tried making maps for Quake (I think I used WinQoole editor?) but my PC was pretty slow for vis compilation, besides I really didn't like the idea you had to have so much excess of geometry that's going to be cut off anyway. Then came Unreal and I was completely sold on how it did things (there the 'world' was solid as opposed to Quake engine where it was empty, a pretty significant difference in CSG), even if original editor would be very unstable and frequently crash. When it came to UT99 vs Q3A I didn't even bother with Quake engine anymore. Outside of FPS games I did maps for Warcraft II, StarCraft and obviously Warcraft III, bunch of unfinished TD maps and RPG map where I went too far and hit the limits pretty hard with editor outright refusing to open the map anymore.
All in all back then I had spent enormous amount of time making maps, sometimes at expense of education and despite how infuriating the tools can often be. It's very rare that a map editor is a solid and polished piece of software (with notable exceptions like Warcraft III editor).
I should dig into backups and archives, I'm pretty sure some of my maps are still there, although a number of bigger things, like a whole custom episode for Duke3D was entirely lost to time (that was the first valuable lesson of making backups).
Also won a mapping contest for UT99 held by a gaming magazine and that got me into game development, but that's a different story and the only thing I can say about it after so many years - don't let your beloved hobby turn into job. Working in the industry didn't bring me any joy and I was happy to leave it altogether, unfortunately it also drained any desire to make maps and mods again for years.