Here's a look at some of my workflow, especially the layers in Inkscape:


They're similar to what's in the tutorial here, but I have some additional things. The rhumb lines are obviously unique to someone who wants nautical maps, but some stuff could be broadly useful:

* 2 sets of city layers, one in smaller size with many cities for regional maps, one in larger size with only major cities for zoomed out world views
* Climate lines, that show the tropics and the arctic circles. This is useful as I'm laying out terrain to make sure I'm placing things roughly at the correct latitudes
* The "Terrain type" and "Mountains bound" layers just have really rough shapes outlining where is going to have hills/forest/mountains/etc; I fill those in with detail on the appropriate other layers. But I can just rough outline them so that if I get bored with placing mountains I can move on to something else and yet still know (and see) the extent of where the ranges are going to finish up.
* "Coastline scratch" is just a quick sketch of where the continents are going to be, done at a totally zoomed out (entire world view) level. That lets me rough out where the continents go, then I zoom in to continent level and draw the actual detailed continent's coastline. For now only the 2 local continents are done in detail, but I can zoom out and see where everything is and can have people in the world talk intelligently about that spice traffic with the continent to the southwest or whatver.
* "Coastline hand" is a hand-traced version of the coastline, so I can have some maps that look more hand-drawn and less detailed.

I had a "coastline concentric" layer for the concentric continental shelf lines (seen in the nautical chart above) but I'm going to redo those somewhat so it's missing at the moment.

Layers are trivial to add and remove and give you tons of flexibility, so may as well use more rather than less!