Anyway, I've been asked a few questions about my process at times, and most of the time, they are simply answered only to the person asked. I have been asked on a few occasions how I go about making my levels. This process changes per level/map. It depends on the complexity and general flow, BUT most of them do start out the same way.
|An in-progress interior level.|
Here's a shot of a map that's still in the layout/planning process. I'll usually start with an empty grid (16x16 pixels per tile, sometimes 32x32) in a paint program and pencil in the static level collision. Giving myself notes and such on the image of what should happen, what I want the player to do at times, and all that.
The colors of notes/scribbles don't usually mean anything specific. Since I'm the only one looking at these, I don't have any sort of standard for that. In groups, this would obviously be different. They're usually drawn to scale so I can drop it in the game as a static background in the map editor. For both quickly getting the collision done and play-testing/tweaking. At this point, changes are super easy and quick to make. The screenshot above is indeed in-game.
Once the graphical details are tiled in, it takes a lot longer to make changes, so I like to tweak the level before moving on. Sometimes even before this step, the layout (with notes) is drawn on paper since that's even quicker. The lines in the screenshot are clean and straight, but I have a quick method for that. (Yay shortcut keys.) There are times when the graphical details are made as I go. For simpler maps, usually boss rooms, I'll do this. Even if the layout needs to be changed later, for these maps, it isn't a hassle at all. The more complex a map is due to anything, be it enemy/trap placement, puzzles, etc, the more planning that goes into it.