Recommendations for WorldBuilder new map creation?

[vonJahgmann]

When basing a new map off an real world map or picture, has anyone found a nice way to change the background to the original image and then use the drawing tools to paint over it?

I am asking, because it looks like this is the general process (which really stinks):

1. Sketch a general image (on paper or in a painting program)
2. Grid the image out
3. For each grid, plot out the mappings for each hex
4. Calculate the HxW size
5. Launch WorldBuilder and create a new, blank HxW map
6. Paint the plots. Then paint some more.
7. Add the details. The add details some more.

Basically I am looking for a help to shortcut steps 1-4 so that I don't get into WorldBuilder paint mode and after 3 hours say "whoops, I need another 5 hexes of width. Oh well, start over."

I have some map/scenario ideas I have been kicking around since Civ5 that I never acted on, largely due to how much time I would need to spend to get things to where I want to go with the maps.

If there is a better way, please share!