Recently I became a customer of Hirst Arts, a company which makes molds (called Castle Molds) that allow you to cast your own miniatures-scale building bits so you can make your own buildings and dungeons (like Dwarven Forge's Master Maze, but you create exactly what you want and it's much less expensive). This is my first project.
Assembled and glued, but unpainted. Made of plaster of paris (POP), It's in two parts, the ground floor (left) and the roof (right). The ground floor has several arrow slits, the second floor has some crenelations on the towers, an open hatch allowing the inhabitants to get up and down. The layout of this is roughly based on the Wizard's Tower design by Bruce Hirst (creator of Hirst Arts Castle Molds), except that (1) I added a second tower (in the southeast corner, if you assume you're looking at it in this photo from the southwest corner), (2) enlarged both towers from 1" interior diameter to 1.5" interior diameter (since I'm giving this to my sister so she can use it when she plays MageKnight, and MK figs have 1.5" wide bases), and (3) shortened the tower by one level so it's not taller than the rest of the building. The red marks on the top of the ground floor section are there to remind me that I'm not supposed to glue the next layer of blocks there, which allows me to remove the roof.
The lower level after I spray-primed it black and then painted it with latex paint (Home Depot, Glidden's color "Pebble Mosaic"). The HA afficionnados reccommend standard latex housepaint because it's much cheaper than using miniatures paint (I got 3 quarts of paint for under $30, while that much mini paint would be a zillion dollars). The POP sucked up the wet paint like crazy. After priming it black, it dried a medium gray, but the primer was enough to make the latex stick. For some reason I didn't photograph the top piece.
Both pieces with a drybrush of lighter latex paint (Glidden's color "Fauna") and then an even gentler drybrush with a lighter color (Glidden's color "Scroll Beige"). The drybrushing makes the texture of the bricks pop out and look more real.
Here's the final result, with touch-ups on some nicks and missed spots, and then sealed with spray sealant. Lesson for next time: when drybrushing a multi-piece building, assemble it and drybrush the exterior as a unit so the coloration is consistent ... as it is, this baby is clearly a different shade on each piece.
A view from the top of the building. The stones in the roof are a little rough, but whatevah, it was my first time. In this photo you can see the "murder hole" I built into the roof using the arrow slit bricks, dumping boiling oil or whatever on people who have broken into the ground floor of the castle.
A view of the interior from above. Note that some of the bricks (at about the 9:00 position of the interior) are chipped. I initially closed off the square top of each tower with a couple of bricks but I realized that would make it hard to handle minis in the tower bases, so I broke off those bricks and left some rough edges behind. I think with the drybrushing and such it looks reasonably natural.