A while ago I bought a set of buildings and ruins from ebay, user mikethomas85. They were very clearly made using a 3d printer, but the quality and design is definitely not bad and I’m pretty happy with them for Epic Armageddon.
Painting them involved a simple dark grey priming coat, a mid grey heavy drybrush, a lighter grey ligh drybrush then some added highlights. I also added some stains from a Vallejo smoke wash and bits of cork rubble and flock plus some green paint to represent moss.
I think they turned out pretty well. Here they are with a stand of Eldar Swooping Hawks (not painted by me) on a standard base for scale.