I plan on making a couple of much bigger ones probably at the end on december or january.
I didn't put a lining in but I don't think that as a diaper bag theat it needes it. I used a baby blanket that was 29" x 39". It already had the little car and what not on it and the d rings and strap came from a water bottle holder that we don't use and have like 5 of.
The sides are 12" x 15" and it is 8" deep and I used velcro instead of a zipper because I have a ton of it.