Thraeton is the world I am currently building. I originally wanted to post the map once it is done but I realized it is a good opportunity to post it as WIP to show my work flow as well as getting some opinions before it's completed. I'll post in steps as the work on this map progresses - feedback and constructive criticism is always encouraged.
After I have a general concept for a world I would like to build, I begin with doodling continental outlines until I find a pattern that I like. I attempt to imitate features from the Earth's map for similar locations, and of course I try to be as naturalistic as possible about my coastlines. I already try to keep tectonics in mind when I do this, but the priority is on creating pleasing shapes for the landmasses.
I use a wacom tablet + inkscape, where I employ the freehand drawing tool to create shapes that I add or subtract as desired. So for example, I might have a straight coastline which I then spice up by creating a new shape that I then subtract to create a bay, or add to create a peninsula. It is a highly iterative process, and it takes me many, many hours. It seems I am just never completely happy with the continents I get.
The earliest draft of Thraeton's world's map that I still have is this map showing my attempt at drawing ocean currents:
An more recent version of the world map where I am already very close to the current layout is this:
Even though they are very different I think you can make out quite a lot of similarities between the two, so you can probably imagine how much I forced this map through the blender, so to speak.
Once I am happy with my continents, I try to work out the plate tectonics for the world. First, I place the plate boundaries - this is the step I am currently at with Thraeton. At the beginning the plate boundaries are just generic boundaries, the second step includes defining convergent, divergent and transform boundaries.
The current map looks like so, the thick black lines are the unfinished plate boundaries:
For this map, I recently converted to Equirectangular projection, because I am using Google Earth for visualization. You can sneak a peek here:
http://files.pandemonium.de/thraeton/thraeton.kml
This is a new experience, but one that I find highly useful as I always had problems really imagining my maps as spherical surfaces. Drawing the polar regions is exceedingly difficult in equirectangular map projections, however, and I have to figure out a good solution for making that part easier whenever I get around to it.