i'm sure you could make this "by hand", however i wouldn't recommend it. i have started one in denim & cut most circles with pinking shears! i don't work on this every day-it is very time consuming.
sewing the squares i'm going to use a really tight stitch-more than 12 per inch--that's for sure-don't want to repair that ever!
when you add your squares to the centers, they could be basted in but i'm just going to lay them in w/o sewing them---b/c the stitches will show on the back!
{you will be catching them underneath when you sew the top flaps down anyway} & then i will use a fancy machine stitch on the curves!