Here's a photo-realistic encounter scale map (without a specific scale which is up to the user of the map) created in Xara Photo & Graphic Designer 9 (a vector drawing app) using many of the techniques I use and present in my upcoming map tutorials guide series.
Although certainly ready for a static encounter between a party of adventurers and a powerful nether planes being held in bonds by some powerful spellcaster, the real purpose of the map was a location to use my created lava bed seamless texture which I also created in XP&GD9.
The demon itself is a Poser 3D nude man posed in a forward leaning lunge in this top down view, with wings and horns created in Nendo (a subdivisional 3D surface modeler), assembled in Raydream Studio (my old 3D software application which is no longer supported, but I still have on my old PC) rendered in grayscale only. Once created the grayscale model was imported as a JPG into Xara Photo & Graphic Designer 9, and I drew shapes with the Freehand Drawing Tool where the outlines would be located - essentially cutting away the white background. The orange of the skin and wings are isolated shapes of color with a 'stain-glass' transparency filter applied so that the shading in the 3D geometry of the model itself shows through. This is similar to 'merge layers' function in Photoshop, allowing you to see the color and shading of the upper layer as well as the surface detail on the image beneath - note the inflow of lava into the chamber drops in elevation and oozes into the main lava pool - this was done with rounded beveled shapes stacked above one another over the main lava pool.
Normally I don't include figures, such as the demon, in maps I create, but since this is a prison cave specifically created for this singular, captive demon, I felt it appropriate to include.
I looked up the demon's name from a list on Wikipedia (interestingly from Jewish origins), and Abyzou had a nice sound to it. Whether this demon actually appears as an orange, traditional devil was completely arbitrary, a simple choice by me (really more an effort to achieve a contiguous color scheme with the oranges and blacks.)
I think the seamless lava bed texture works pretty well, in this example.
Edit: oh, here's the link to the thread where I was discussing the creation of the lava bed texture.