I was on a mission to find lightweight, easy to make rocks. These work well for smoother rocks or those in the background.
How To Make Cheap and Easy Model Rocks!
Beginners Guide Part 6: Scenery National Model Railroad Association
Easy to Make Lightweight Foam Rocks - Kathy Millatt Modelling
NMRA RH October 2018
Scenery
Model Tracing
I've been painting my rock face - Kathy Millatt Modelling
Starting Scenery: Rocks - Kathy Millatt Modelling
Modelling Scenery Archives - Kathy Millatt Modelling
How to make polystyrene rocks
Easy to Make Lightweight Foam Rocks - Kathy Millatt Modelling
Spray foam for hills?
Beginners Guide Part 6: Scenery National Model Railroad Association