I'm dreaming about the industry and have made some few levels for unreal, quake, but with tech that is 20 years old by now. I began to read a lot of articles about design, game design, level design and started a site to collect all those readings and write about it myself. I ended up writing much more than really producing practical levels.
The site began after I played some FPS games with bad level design that left me lost with no clues about what to do, where to go. I asked myself "If I were designing a level, what should I avoid? What mistakes can I see in those games that I can learn from?". From that question my site began. The first pages covered some basic visual stuff that I've learned from some old unreal tutorials that are long gone because they were hosted on sites that no longer exist or the author closed his or her own site long ago.
I'm currently on the process of rethinking the site becase as it is now it's a mess. I choose to no focus on any specific tech but stick to concepts. From what I know about my own skills I'm not on that side of producing concept art, illustrations and such. I wish I could learn a bit about AI and 3D graphics but I need also to be aware that knowing it all is not possible.