Controversial here, and already more or less said, but:
Publish a map
Get some feed back on that "trash" map you were thinking about throwing away. When you learn from your mistakes, and make legendary 32-map megawads later on, nobody is going to care that you uploaded a 6-square room map years ago. Popping your cherry and getting a map out there will relieve a lot of anxiety you might have, and will allow other Doomers to find things you're doing wrong you might not have even realized.