I use flour (sometimes colored) for snow, mud, & swamp terrain/terrain features. What do you all use?
Flour is organic and will rot over time, so I would not recommend it.
For snow, woodland scenics, GW, GF9 and several other companies make realistic snow flock. It works the best for most applications.
For mud, using plaster or spackle compound either died brown and/or painted works. Use Future floor polish (It's acrylic) or Testors Glosscote for wetness.
For swamps, basecoat the area to be water blackish green (or greenish black). then use a gloss varnish. then stipple on medium green around the edges for plant growth in the water.