Been visiting this forum every now and again for a while now. Always great to see so many different ideas so thought it fair I post something of what I use.
The following maps I put together for a Play-by-Post 4E Dungeon Delve. The focus of that particular game is on the combat and the mechanics of it so I wanted a fairly clear map that wouldn't leave too much room for confusion but I couldn't resist trying to give it a little atmosphere as well.
I spent most of the time developing the photoshop layers and effects as all the walls and levels are effects and I just draw each stepped layer as solid white. The floor and solid wall textures were created using a mixture of filters and again using solid white for where the wall is and let the filters colour and border it.
The two maps are using exactly the same template and just a redraw of the mask layers. Though possibly I did make a change to the solid wall effect as it seems significantly darker on the second and later maps.