[phiwum]

I've added an image of just the megahex borders that can be overlayed onto any hex map. You'll have to resize it to fit the hexes, obviously, and this is a bit fiddly, but someone may find it useful.

Two examples of maps I've made using gimp:

• A simple excerpt of a labyrinth map, where I use brown to indicate a higher level.
• A more complicated roadside inn and stable.

Both are fairly simple to make, though the second took a lot longer than the first. I use additional layers for GM notes (monster locations, traps, etc.) and hide those when creating the png for roll20.net, which players would see.