I have been making baby receiving blankets for over 40 years.  I made them for my kids, grandkids, and now my great grandkids.  I have made many for baby shower gifts and everyone loves them.  The secret is to buy one yard of flannel, wash it  and dry it on high to create any shrinkage.  When you take it out of the dryer, iron it to make sure it is smooth.  Fold the fabric in a diagonal, and cut off the excess.  Use the excess to make a burp rag.  Take the blanket and fold the edges two times 1/4" to make an even hem all the way around, and press tight so that the hem is secure, then use your zig zag with a "cute" pattern and secure the hem.

The excess material, fold in half inside touching. Sew with straight stitch leaving a 3" opening at the top.  After sewing, turn right side out, and press.  The secret is to iron all seams even, then top stitch with the same zig zag stitch, and you will have a beautiful set of receiving blanket and matching burp rag to be proud of!  This makes a square receiving blanket that you can swaddle any baby in with pride!