The figure on the left is a test using Citadel Sepia Wash over a base of Tausept Ochre, though any light 'sand' colour will have the same general look.
The effect is somewhat darker and more pronounced than you see here - the camera flash washes out the depth of the colour. I checked the mini again after downloading the photos and found the contours and creases are easily visible at a distance of around 4ft from the eye. There is a slight knack to using Citadel washes. I'm certainly no expert but here's how I used the wash on this miniature.
First wash the whole figure with the Sepia, not too much pigment this time round! Then let it mostly dry (I'm impatient when it comes to painting miniatures). Now fill the brush with pigment from the bottom of the jar and roll it on a paint palette to take out the excess medium. Then 'paint' the heavily pigmented wash into the creases, folds and crevices. Unlike opaque acrylic you just have to give a quick swipe with the brush. The pigment will (almost always) settle in the lower creases, leaving the raised areas as highlights. You can leave as is or build up the depth of colour as you want with further applications.
The Sepia is 'warmer' and more subtle than Devlan Mud. In the instance above it provided a finish which reminds me of faded British desert cammies.
Overall, not bad at all for a 'quick' finish when you consider it's just basecoat and wash. You can go to town with highlighting, drybrushing or weathering if you wish, but if you need a platoon of desert troops in a hurry.....it's now a matter of detail and you can probably complete the lot in two to three nights, start to finish.