I have a base 29cm x 37cm. The terrain is desert and the scale is 1/100. Do you have any ideas on what extra things should I put like rocks and such. The dio looks very plain to me. There are 2 Gundam mechs fighting in the desert and that's it. I need some additional background to spice things up. Thanks!

For a desert I would look to add a rocky pile with some wispy shrubs. In that small a scale I would look to use stuff the size of kitty litter and use white glue to secure it. Then build up around it for wind blown sand. Use putty, spackle, or celluclay to fill in the gaps. Then paint it to blend in.
Shrubs could be paint brush bristles clipped and dabbed into a drop of glue.

How about an old dead tree, use a root from an old plant from the garden. Dry it out in the microwave and add some dark washes to give it 'texture'.

If you want to add a human factor - how about a stone fire circle as the left over from a camp out. Dab some black in the middle for the left over camp fire. Maybe some tracks from a jeep or something.