Thanks everybody for the good feedback.
In regards to the legend, I was hoping the content was generally self explanatory. But you're right it's probably better to include one anyway.
For the contour lines, I used a raster mask of the ice layer in black for the brown lines and then inverted it on a copy of that layer (actually two layers - one for index contours). I learned this from Adam Wilbert's tutorial on vimeo, which was a great help.
Yes, that is a purple hillshade on the ice. What I did there was I masked out the original hillshade with the ice layer and replaced it with a colourized and brightened purple hillshade. This is done in photoshop using the hue/saturation adjustment layer and ticking off the colourize layer. I also did the hypsometric tint by colourizing and blending copies of the DEM. For example, I used an inverted copy of the DEM as a mask on itself and applied a green hue to it for the lower elevations. I believe you can also use the 'gradient map' to create your tint, and this may in fact be a better way, but I haven't really experimented with it yet. The additional green texture on the fan is actually a 'wooded' layer I overlayed with a light transparency. I hope that answers your question. There's really so much you can do by just experimenting with all sorts of masks, blends and transparencies in photoshop, as long as you have a good idea of the result you're after.