With the increase of maps being made and being accepted for submission into Red Eclipse, I thought I should maybe share a few of the things I look for (or have to fix myself) when considering something for inclusion:
Variables are set correctly. This includes "numplayers", "maptitle", "mapauthor" and "mapmusic". Too many times have I been given a map which read "Untitled" by "Unknown" on the loading screen. Does your "obitdeath" or "obitwater" make sense? Note that the music is just as important as anything when creating the "theme" for your map, and you can provide your own music so long as it fits the overall theme and licensing requirements.
Proper placement of entities. There should be at least two weapons for each player you intend the map to hold (eg. 10 player map would need roughly 20 spawns), PLUS any specials like grenades and/or rockets. They should most definitely NOT be placed all in a bunch, please spread them out over your map. You should have the correct number and types of player starts for your map size and mode types, the same goes for your affinities, these act as flags and/or bombs/goals in objective modes. Have you added atmospheric particles and sound effects to increase the mood?
Good use of lighting. Is there a sunlight being used? Could the map have better ambiance if it were lit more sparingly? Is the lightprecision up high enough to create at most 3-5 lightmaps? Could skytexture be applied to outer zones to reduce the overall lightmap count and rendering area? Are things of significance clearly visible? Does the lighting suit the area (does it have a source)?
Flow intended to aid good gameplay. Is there a good enough mix of corridors and open areas? Can the player get around easy without getting stuck (hint: clip/noclip)? Does the map account for features such as parkour? Can the player get to any areas they shouldn't? Does the map run at a decent frame rate (hint: use occlusion)? Does the map play as well as others included in the game?
Attractive textures and materials. Nothing screams masterpiece like something that you want to play from the moment you see it. Make use of the large array of texturing options and materials. Could you make this scroll/pulse/whatever? Could you add some trim here to break it up and give the area some depth? There's grass there, could you maybe use a few bush mapmodels too? How about using a blendmap to create a path from this point to that one?
License and package appropriately. Make sure your map is only "mapname.mpz", "mapname.cfg", "mapname.png", "mapname.wpt", and "mapname.txt". Your license should be included in your "mapname.txt" (note: if transferring a map, this file will be sent as well); try to avoid generic names like "readme.txt" and "license.txt" because I have to fix these myself before putting them in the game.
I'll add to this as I run into future issues. But that should give you the idea.