I actually posted this as a thread response in the finished maps section and figured I'd add it to the Tutorial section. I'll try to add additional tips as I find the time.

Here's a link to the original thread: Cormyr Map

A little bit of my process:
Using a 6x8 Wacom tablet and Photoshop CS3 I lay down my inks first and send them off for approval. Once I've received any changes/notes I go in and build up the colors and textures in the final version and hope there are no additional changes before handing them off.

I typically start by pasting any reference sketch I have into a layer set to multiply with a transparency of 20-40%. If I'm working on a tactical map this allows me to stroke an accurate grid on another layer using the reference as a guide for path setup. Once I've layed out and stroked my paths and have a grid layer appropriate to the map, I set it to multiply with a transparency of 30-40% and then create a white layer mask for it. The white layer mask allows me to hide or obscure portions of the grid without damaging the actual grid. I can hide/reveal the grid by just painting on the mask.

To keep my inks organized I put wall edges, surface details, etc. on separate layers within a general Inks folder. The reason for keeping certain inks on there own layer is that if there are no breaks in your ink line you can quickly use the magic wand to select areas by simply clicking with it in the area of the ink layer that you want to select. One warning though; when using ink edges to define selections you must expand or contract the selection so that it overlaps the edge of the ink line by a pixel or two. Otherwise when using that selected area to fill with a color, for example, you may end up with odd halo effects.

I keep my color layers organized in their own folder below my ink layers and place all the tags in their own folder on top of everything else.

ok. I'll quit rambling and come back later with some more tips and tricks.

Mike