R1ck

I like to make the layout first, or at least most of the layout. It helps avoid mapping myself into a corner or feeling like I'm stuck with an area I put lots of time into that I want to change or replace later. It also makes it a lot easier to plan for big setpiece stuff like transforming rooms, which are only really feasible in Doom if you already know they're going to be there before you start detailing.

I'll usually still end up changing and expanding on the layout somewhat while I'm detailing it as more ideas come to mind, and maybe adding some extra secret areas based on the detail, like walking along trim ledges to get someplace, or having a way to access part of the surrounding scenery.

When you start a layout unfinished and begin detailing as you go along, you are making your map "heavier."

What I mean by this is to imagine something like an empty bookshelf. Its pretty easy to lift and put elsewhere in your house, arrange the shelves how you like it, etc. However without books its not a very useful piece of furniture. However if you load the shelves up with books immediately that dont fit on the shelves, and the bookcase happens to be in the middle of your living room instead of along a wall where its out of the way and doubles as a decoration for your home.

The bookcase in question is a simplified example because its much easier to take books off a shelf so you can move it elsewhere in your house than it is to strip a map from detailed to basics so you can change its size and shape or add some hallways to it.

When you begin detailing your map, you are committed to the idea that this particular part of the map is complete and will not need to be changed later. You don't really know this without playtesting.

I've learn some nasty lessons by trying to detail while the initial mapping process. Especially shading. Great tips above.