So I took one of my really old prefolds (gerber store bought, used for burp clothes last baby) to practice making fitted diapers. This was my first attempt and didn't turn out too bad. The cut our regions of the prefold were used to add more absorbancy to the center. The back tabs are more symmetrical than what the picture shows, the elastic just makes it sit funny.
I also had TONS of white onesies sitting around (never used them from the previous pregnancies cause i prefered colored ones)....so my daughter (4 years old) and I spent the afternoon dying some.
Pics below