I make all sizes, too. Most of the baby quilts I make are bigger--around 50-62. I do not know what they end up that size...it just seems like that is the size I make them. I do how ever want to start making baby quilts smaller. Till I can buy the packaged 45 x 60 batting, and not be cutting up bigger battings for them.
I tend to start with an idea for a quilt and just wing it.
This one I started with just making little 4-patches. Then later I decided to use them as the corners of 9-patches, and it just went from there and I really liked the result. Not all are as good as this.
I have made two or three that are approximately 90 inches square...I have made one that was 87 inches square..and have made others that fit a full bed but probably most people would use as a twin. I don't like a lot hanging down so I know I am different in that.