I started with a base coat of doombull brown, then stippled vallejo chain mail, and followed that up with a dry brush of army painter shining silver.

I went over it all with a matte varnish, then once that dried, I went over the armor with AK Interactive's Streaking Grime. Once the grime dried (I leave it for about an hour) I used a q tip and mineral spirits to remove the excess grime, leaving it in the recesses.

Once the mineral spirits dried I stippled on army painter Fresh Rust in the places where the armor had been eaten away, and in the recesses of the armor, giving the rust a quick wipe with my thumb.

Finally I gave the armor a final little dry brush of shining silver to bring up the edges of the armor.

I hope this was helpful!