So I had the genius idea of buying four unfinished wooden crates from Michael's ($12.99 each), spray painting them white, tacking them together and then bolting them to the wall.
The problem with my "simple" DIY construction projects is that while I'm the designer and enforcer, my husband typically gets stuck as the implementer. And because he actually has some knowledge of how to do such things, he always uncovers quite a few flaws in my plans.
For example, the spray paint, which I thought would be faster than painting with a brush, failed. Miserably. So he resorted to using several coats of some paint we had left over from a recent bathroom trim project.
Then it took multiple iterations of bolts and screws to secure the crates to each other in a way he felt would be safe when Cricket got her hands on them. And then there was the standard debate of how best to anchor the finished shelf to the wall.
So the project took a bit more effort on his part than I anticipated, but I kept reminding him along the way that we were saving money by constructing the shelving ourselves. (Somehow the reminders didn't seem to improve the situation.)
The undertaking immediately seemed worth the hassle, however, as soon as Cricket saw the shelves in her room and exclaimed, "Oh!" as she ran over to investigate. Now we just have to fill them with her special books and toys.
(You can check out the completed toddler bedroom here and the nursery here.)
We stacked the crates, then drilled two holes into the center of the two middle planks of each shelf. (Photo below.) We used 3/4-inch bolts (screw plus nut) to secure the bottom of one crate to the top of the one below it. We made the opening of the holes wide so the top of the screw and the nut on the bottom side could recess into the wood (and not snag). The screws are visible on the shelves, but of course they are covered once you fill the shelves.