I cut my fabrics with rounded corners. One is a minky (or as Fabric Depot says, formerly minky), the other I call a slinky.
I also cut satin for a binding. Babies do like satin edges.
I serge the satin because it is a great raveler.
I sew it to the right side of the slinky. I put 4 pleats in the corners.
I baste all the sides of the minky because it has a great tendency to stretch. This way I can ease it into it's spot.
I pin the minky and slinky right sides together. It's good to use lots of pins.
I then sew them using my walking foot, easing as I go. I leave an opening of a few inches for turning.
I turn the blanket right side out and check for tucks that take a little repairing. They do come. When all looks good, I hand sew the seams together.
I press it on all sides and then do a top stitch (again with my walking foot) around the whole blanket.
Now I have 4 beautiful blankets ready to keep babies soft and warm.
I've had problems in the past making these, and I'm thankful for all the help I've gotten off the web. The internet can be a great service in helping us improve the things we do.