I use super fine hobby ballast with a small ammount of a little larger ballast mixed in. I also add large fish tank rocks to my based in places to break them up some and add a little extra pop to them. One of the big things to do when working with sand is sealing it, with a 50/50 mix of glue and water( i use Titebound wood glue for all my bases). Once thats dry you can pick a brown of your choice not to dark do a 75/25 brown to water mix and just coat the ballast with it, once dry use the agrax earth wash from GW on the rocks and it adds a nice contrast for the bases. I'm a fan of the fake grasses for bases it adds extra detail, as well as flock i'll post some examples of my work.
Did some drybrushing and once done added in some black washes in spots to break up the uniform of the colors.
Dark color with a mix of flock and fake grass, 6mm fantasy giant cyclops from Microworld. Once the flock is secure i soak it in super glue it drys hard and won't get knocked off.
Just used fake grass here with a dark base also.
Lighter brown with the dead grass from GW, I really like this grass it contrast very well with the miniatures and bases.
Same technique described but i added extra drybrushing to the base to make it pop more, the fake grass is a silfor tuft from GW.
Bunker objective same style as above.
Blind-
I'll add my 2 cents ...
