I have been using HeavyMetal Map hex grids and colored pencils to create custom maps for a while now. I don't have the finances to create diorama style maps, but I was thinking playing around with some new home made map styles. For example, I am currently considering buying a large roll of hex pattern printed paper. I was thinking of hand drawing a map and then attempting to paint it. Afterwards I can frame the map however I like in order to make it more durable.
For /gaming/ purposes (not to get the best looking maps) we've found that using a large hex-printed sheet (I have a roll made by Highball), and then printing (using HMMap in my case) areas, usually no larger than a letter size sheet, of various terrain, mountains, woods, lakes, etc. works quite well. A dozen or so separate sheets can be placed around the large map, resulting in a new map for each game, looks good, and is cheap. We've even made many of these components 3D, to be used either with flat map sheets or 3D maps. It's just a way of getting a lot of good looking variation, especially with larger (2x2 and up) map areas, without much cost, but they still play well and look good. Obviously, things like factories, buildings, dropships, etc. are done the same way.