I screwed up when cutting it out; I put the wrong edge of the pattern on the fold of the fabric, happily repeating the mistake for two outside pieces, two lining pieces, two canvas reinforcement pieces and four internal pocket pieces. Ack!! So now all those myriad bits have a seam up the middle, which I camouflaged on the outside with a strip of dotty ribbon.
It was my first Amy Butler pattern, and I found it very easy to follow (the mistake with the fold was completely my fault, not Amy's). The finished bag is pretty heavy (thanks to the canvas reinforcement) which I'm not sure is a good thing for a nappy bag; but at least it's super sturdy.