I've been practicing using Ultimate Doom Builder to make Doom maps. I'm obviously not a pro yet, but I think my practice map is looking somewhat decent:

An image of a custom DOOM II map, showing a room with four pillars and a skylight. An image of a custom DOOM II map, showing a room with four pillars and a skylight. An image of a custom DOOM II map, showing an open area with rocky cliffs. An image of a custom DOOM II map, showing an open area with rocky cliffs. An image of a custom DOOM II map, showing an open area with rocky cliffs.

I also used ENDEDIT to make a custom ENDOOM screen for when the game closes while the WAD is running. I'll definitely need more practice using this, too, but it was good to test if I could add a custom ENDOOM screen to the practice WAD:

A gray screen with black borders at the top and bottom, and blue borders at the top and bottom edges inside those black borders. There is text that reads 'This WAD was created by: ArtistPanda5. You can find my contact info at: artistpanda5.neocities.org. DOOM II belongs to id Software and Bethesda Softworks