There are some classic isometric dungeon maps out there, particularly those of castle ravenloft - the original David Sutherland maps inspired the styles of all maps of that castle that have come since. It's also a style beloved of computer games, most notably the Diablo series.
Creating an isometric map is actually pretty easy:
1. First draw out your floor plan as if it were top down. Place lines for all the elements on the ground - walls, doors, outlines of pit traps. I draw these lines on a separate layer from the grid as it keeps everything organised.
2. Make it isometric! Rotate the map 45 degrees. Then you shrink the map vertically by 57.7%.
3. The great thing about isometric maps are the vertical details you can throw in there. Find every corner, and draw a vertical line to show wall edges. Focus on the edges that don't obscure details further away. Here I've added the most detail where the detail doesn't overlap the actual floorplan. Fill in the blank space with sketched stone texture, add in illustrated doors, throw in some lines to show the rough stone in natural stone tunnels and give the viewer an idea of just how deep the spiked pit trap is. Again, I add these details on a separate layer to make it easy to erase mistakes without rubbing out the floor lines.
Remember that the primary goal of the map is to show the floorplan and allow for easy use for a GM. The extra detail that an isometric map provides can really sell the setting of a map, but it's also easy to obscure important features.
This originally appeared on G+ here: [link]