How do you design your maps?

[Habluka]

In the case of the only map I've ever actually released, I sort of drew out some guidelines for it on some paper that gave some notes about how it should be textured, the heights, the sizes, and the floor plan. Of course, I don't always do this. In my most recent map, which I do not feel like releasing, I was just frustrated that I couldn't actually play very well on the computer I'm using, so I started messing around.