I was first introduced to diaper cakes at my baby shower, they were the table centerpieces. While they made an adorable decoration, they were also incredibly useful as I went through the first months as a new mom.
Now when I have baby showers to organize or go to, I'm always sure to find out if someone is making a diaper cake, and if not, I try to bring one. Here are a couple of photos from some made not too long a go for a couple I work with.
This first one shows that there are rubber bands holding everything together under the ribbon, I pulled the ribbon down for the photo.
I rubber banded about 6-7 diapers and then put them inside of a large rubber band for the base. I rolled more diapers without a rubber band and secured them inside the large rubber band set so I wouldn't have to be hiding rubber bands everywhere. Once I had the base the size I wanted, I went ahead and did the same thing for the other two layers, rolling diapers and sticking them into the rubber band area.
When my layers were the size I wanted them, I used 3/4" to 1" ribbon and wrapped it around the rubber band holding everything together so the rubber band was hidden from view, plus the ribbon adds a nice finishing effect. You can tape the ribbon with clear tape, I used a pin needle to pin it in place.
Cost of the project: under $30 for 2 diaper cakes, not bad, especially if you know you have 2 baby showers coming up!