This is going to be embarrassing as hell, but, in order:
Cp_Oubliette
This map I learned the basics of hammer and was my first playable map released into the wild. I learned about corridor/ room syndrome and the very basics of a fun tf2 map. There was very little worth playing on this map, but it was a good first start. Also I love this map name and need to re-use it sometime.
Cp_SmugDotGif (never came up with a proper name here)
This map didn't make it far, but it was my "I'm going to learn how to do displacements by making a map almost entirely out of them" map. It was also an experiment with height advantage/ flanking routes. I learned a bit of optimization related stuff here too.
Artpass_UEAKCrash
This map was all detail work, obviously (it was part of the artpass contest that spawned Mann Manor and Mountain Lab.) Learned a ton of detail tricks here, and really showed me how much fun detail work is.
Koth_Cenotaph
This map taught me how 3d skyboxes worked and a lesson on over-complicating and over-detailing a map too early on. The layout didn't really work for the game mode, and I actually ended up converting this into a Vs Saxton Hale map eventually. Didn't promote that much though. I should mess with that a bit, actually. Also another awesome name. My names rule.
CP_Volkar (another temp name. Named after a D&D character of mine. Should have been
CP_2Horse)
This map taught me how no one likes medieval mode. Also how vertex editing can break brushes into invalid solids. Got a BIG lesson on that one with those god damned horses. Also taught me how to do spiral staircases and how much people hate spiral staircases.
Pl_Crash
This map taught me about gameplay design a ton. I also learned (for the most part) how payload maps are set up/ work. This is my project where I forced myself (finally) to mostly work in dev textures and not worry (much) about detailing as I designed. Also how multistage maps and forward spawns work. This is still sort of on the backburner and might get picked up again, but I've learned a lot since then.
CP_Stoneyridge
This map has taught me a ton about clipping (I am for the most part the only clipper on this project,) detailing, optimization (so much,) working with a group (three person project,) lighting, gameplay design, and most importantly, how to move a map through the testing process, get it in players hands and when/ where to cut when necessary. Working with a project "lead" that is
more experienced than I am helped me understand this whole process so well. We cut a TON from what the map was originally, and he really showed me not to get too attached to any aspect of a map you're working on, as things just
need to be changed sometimes. I learned how to take feedback here too. This one is close to release candidate 1 VERY soon.
Koth_TrainSawLaser (unreleased publicly)
Have a video instead of a picture.
This map showed me not to take mapping too seriously, and that a simple design with a catch can be a lot of fun. Dick-around maps can be an awesome way to take your mind off serious projects and just plain have fun with others playing your map. I play this one quite often still. This taught me how exciting it is to have players really enjoy your map and has given me a feeling to strive for with my future maps.
Koth_72_Crash
This map taught me how to map in a short time frame and optimize my personal workflow. It also taught me how to pre-plan efficiently and prepare myself for a large project. I also learned a lot about gameplay design and when and where to use underground routes that are barely connected (sparsely.) It also got me thinking about designing for the competitive scene, specifically highlander mode. I learned a lot about sight lines with this project. I made this map from start to finish in 52 hours of the 72 hour time span allotted. I lost my mind on this project, and it has yet to return.
Koth_Aquifer
This map is a continuation of my 72hr map for STAR's contest, which is wrapping up soon. I'm actually neglecting working on this map like I should be to type all this up, heh. This map has solidified the importance of height advantage and a lot about how to understand/ interpret feedback coming at me. I'm picking up a lot about subtle/ not so subtle cues in map design and combat flow (thank's yyler!) Health/ ammo placement is extremely important to this gamemode and the competitive scene in general, so I'm working on making it perfect. I am still learning a lot from this map, but it's hard to tell at this stage. Ask me in a few weeks after it's released for the contest.
Yeah, sorry if I went overboard here. It sounded like fun recapping my mapping career and at the very least can show you how I progressed from a total noob to a (somewhat, imo) competent mapper. Hopefully you can learn something from it.