Terrain

Light/Heavy Woods (heavy=left light=right)
To create woods start off with a pack of railroad terrain trees. You can get these at any hobby store where they sell railroad sets. Use the instructions to assemble/paint the tree. Make sure you keep the excess foliage. When they are all assembled take a 1/4 inch peice of wood. width and length don't matter much. Drill 1/8 inch holes in the board an 1 1/2" away from each other. File down the edges to create a slope to blend in with terrain. Paint the board forest green with water paints. You'll probably need more than one coat. When the paint has dried, smear a glue stick all over the top of the board and sprinkle your excess tree foliage over it. Then insert trees into the holes. Every 1 1/2" for heavy trees and every 3" for light trees.

Pavement
Pvement, there are two ways to doit. The first is to use cardboard and paint it in grey, and then you can put roads or whatever on it. The second, easier way is to use the flat grey foam that you get in boxed sets of miniatures. Unfortunately it doesn't paint up too well so you can't paint on roads, sidewalks, etc.