Recipe for scatter terrain items,

1. Prime the model is Chaos Black
2. Cover the model in a patchy coat of Graphite
3. Heavily wash the model with Rust Streaks and Light Rust Wash with varying consistencies
4. Remove some of the enamel washes with mineral spirits to soften or blend the areas.
5. Varnish the model with Ultra Matte Varnish
6. Additional Step: Pick out metallic parts using sponges and stippling with Decayed Metal and Canoptek Alloy
7. Additional Step: Use Medium Rust Deposits and Dark Rust Deposits to break up previous rust washes.
8. Additional Step: Create pools of grease in moving parts with Engine Grease and fade out the edges.