Mick..
In a nutshell use polystyrene tiles to build up hills etc or blue foam all of this can be cut to shape. I use a lot of parcel packing on items I buy as base blocks. You can then use a cheap plaster or, celluclay even modroc bandage to cover and there are your hills etc.
I use scenic shovelled snow and glue each layer down to get realistic snow but, if you don't want it permanent just spread it around. I make my own grass with a static grass maker and, then add winter effects to it. You can buy really nice trees made from woodland scenic but, its easier to use balsa wood and some thin wire to make the tree and, add foliage on the market to make trees and bushes. I use an airgun to winter the foliage but, a brush with most of the paint rubbed of works just as well to get that winter feel.
Some rocks stones either what's lying around outside or made from moulds adds the extra touches. Any further help you may need just PM me
A decent source of info is You tube type in dioramas etc and, you will get lots of tutorials
Mitch
