>>1682376
This is going to be subjective to everybody. Some people like big open maps, some people like cramped maps. Some people like small maps, some people like huge maps.
To me, a map isn't just a map, it's a level in a larger set. I realize not everyone makes maps this way (especially if it's for, say, a community project like our own 200mins project) But you should keep that in mind and kind of work your shit around that. For example, if you have two long, expansive levels, the next level should be pretty short and relatively small, to give the player a kind of "break" before they enter another large level where they might get lost.
In addition, the best maps do a few core things pretty much always:
-Always change floor height if you want to change floor textures
-Inset your doors; that is, put a little "doorway" between the actual door sector and the room. Look at E1M1 for an example.
-Pick a texture theme and stick to it. If your map is techbase, don't randomly start throwing Hell textures into a room in the middle.
-Try to make each room unique to itself within the level. By this I mean, you can have multiple levels with "computer rooms" that are similarly designed, but try not to have more than one "computer room" per level. This way the player can use those rooms as landmarks. Ideally, every room should be easily remembered by the player. "Oh, this is the room with the blue carpet and high ceilings." "Oh, this is the outdoors area." "Oh, this is the green walled dark sewer part."
-If you make a window to outside, make sure the player can get to that outside area. It's more fun that way and it's a great way to come up with secrets
-Try to make sure your level has a progression to it. When making a monster encounter, think about what equipment the player is likely to have at this point (both from pistol start and from previous levels) and think about what kind of threat is appropriate.
Best bet: Trial and error. Make a map, see if other people like it.