What is the suitable material for a desert terrain? I tried using aquarium sand but it looks more like a beach. I also used plaster of paris and paint it with desert yellow but it doesn't look much of a grainy sand in 1/35 scale. Suggestions?

If you're not pleased with the outcome of what you mentioned you can try to use kitty litter and crush it to the point you are satisfied.
I personally use a bit of play sand, a bit of dirt, and some kitty litter to vary the size of the rocks and sand.
Also remember that in certain areas the desert is very rocky and larger size rocks are approrpriate. I have VP Making Dioramas Vol II "Desert Raiders" is a SAS Jeep and the texture is quite varied from small sand to kitty litter size stuff witha few large rocks thrown in too.

I use sifted fine sand thru an old (it better be! ) nylon stocking. Applied to the surface with diluted WG then paint.

Another option, if you can find an English school, is to ask them a bit of the very fine quartz sand the kids use to play with, then follow what Slodder said and you'll get a very good mix.
Sprinkle it over white glue thinned with water, paint in desert yellow, wash with a bit darker shade of it (add some brown/dark brown) and then dribrush with a lighter one (add some white). This is the way I do it, but I'm sure that there are more suggestion coming from much more qualified vioces than mine regarding dios...
Ciao

Well Shonen

Depends totally on what kind of Dessert terrain you want to make.
Mostly the dessert grounds consists of 80% rocks and 20% sand. and then the grain of sand differs or the size of the rocks even the colors differ enormous.
I usually Make a ground with every leveling made up out of styrofoam. I cover that with a layer of wallspackle sprinkle some kitty litter over it till I`m satisfied with it. Next I sprinkle the sand on it while it is still wet. Then I let everything dry
When it is dry I spray everything in several tones of brown as shaders and then several tones of yellow (dessert yellow and such)
This would make a good base or your Dessert groundworks

Hope this explanation is of some help

Although this is suppose to represent North Africa, I think the desert terrain will work for any desert area. It is made from Durham Water Putty (– you can buy at most hardware stores and Home Depot).

I drill 1/4 in holes into the base to give the Water putty something to which to adhere. Water putty works just like plaster – mix it pour it, filling in the holes and covering your base as desired. I work in the terrain, and any special features – large rocks (minly made from old broken up Water Putty that harden at the bottom of the mixing bowl) ravines, washes etc. Then I sprinkle dry Water Putty in irregular patterns over the still wet putty. I made a sprinkler out of an old 35mm film canester, with 10-14 small holes punch into the lid - like a salt shaker. After making several passes I sprinkle some fine street debris (that stuff that sits in the gutter or street curbs – it tend to have fine to small grit and rocks and pebbles in it). This allowes for an uneven spread of the materal to give ita grainy effect. Then I make my tracks or wheel marks, footprints, etc. After it dries I use my air compressor and blow off the excess. Several washing with burnt umber and dry brush to the desired color and texture.

Durham water putty is my main source for dirt, snow, building, walls, cobble. Check ebay and see if you can fine a great (Out of Production) book by Ray Anderson. I believe it wads published by Kalmback – Fine Scale Modeller.

Good luck,
John
www.johnneill.com

I have had good luck with Plaster of Paris and stuff from the side of the driveway or road check out the ground work for a M3 Lee of mine. http://f1.pg.photos.yahoo.com/bf443 it might give you some ideas at the least.