I have been wanting to make a large office building piece for sci-fi and superhero games, so I bought six white miniature milk crates as a base to make these simple buildings.
This crate is from Office Depot (item #785-255) and unfortunately it appears to be discontinued.
The first step is to remove the curved section of plastic at the top that imitates a handle. I found that the easiest method was to use a Dremel to cut through the thicker sections, then I cleaned up the cuts with a utility knife.
Next, I made the pieces that will fill in the windows on the sides of the buildings. I used cardboard from cereal boxes and similar packages, cutting them to fit the inside of the crates. I taped the pieces to a board so they would not warp while drying and used a broad, coarse brush to make the streaked pattern seen on these pieces.
Here are the window pieces glued in to the crate with white glue. One of the windows has been filled with white to match the crate.
Next, I filled the remainder of the middle row of windows with white, making an area that represents the separation between floors of the building. Some touch up on the windows is still needed at this point. To have a flat, dark surface on the roof, I cut a square of black craft foam material, applied some spots of dark gray, and used hot glue to hold it in place.
Here are the six crates finished and stacked together as one building. I am considering making some low walls to surround the roofs and other items like air conditioners and stairwells that might be found on roofs. Ideally, these would be stored with other small items inside the buildings.
Along with new buildings, I made a simple set of street lamps. They are made from mass-produced wooden parts: 2.5" shaker pegs and doll stand bases.