I occasionally browse freecycling ads in my area for interesting porcelain, vases, flower pots and furniture that will fit into a small car. There are Billy bookcases and bookshelves aplenty, and since they’re so common there are few who are interested.
I managed to get hold of an older variety of Billy with a width of 75 cm (around 29,5 inches). This fit perfectly within my coat closet, which has an exterior width of 80 cm (31,5 inches) and an interior width of 76 cm (29,9 inches). All I had to do was measure the free space between the bottom shelf and the bottom of the hanging coats, then mark the sides (from the top).
I cut the sides to the right height with the help of a crosscut saw (I didn’t have a track saw at that time). Then I sanded the raw edge, fixed the middle shelf with screws so that the construction wasn’t wobbly and “installed” it (merely put it in). In the span of ten minutes (not counting picking the bookshelf up, clearing out the closet or putting the shoes back) I had a basic shoe shelving unit that fit my needs without any bells and whistles.
If it gets too scuffed and I have the spare time, I’ll just paint it.
What did I do with the rest? Was considering a doll house with gable roof, but my kids have outgrown that phase, so I saved the scraps for a future project.