Once the filler was dry, it was sanded down to get rid of any sharp edges or peaks that might be on the piece. A door was made in the front out of card and a handle was taken from a tank model. A thing was glued onto the piece and a couple of straws were also glued on as exhaust ports.
The building was brushed black and drybrushed a dark grey, light gray and finally white. The door, exhaust ports and thing were drybrushed silver. This piece is so stable and strong it wasn't even based.
The second piece is a small bunker I built from offcuts of styrofoam from making hills. It is based on a square of foamcore with masking tape around the edges to hide the foam in the foamcore. The bunker itself is made of "bricks" of styrofoam glued to the base with a removable roof.
The bunker was also coated in wall filler, but a brush was used after application to give the bunker a formed concrete look, much like that on the highways and interstates (at least here in Minnesota). Once the filler was dry, the bunker was painted black, and drybrushed from dark grey to white, just like the above piece.