I recently made two pairs of flannel pajamas. I used THIS pattern. Because it was made for stretch knits, I had to change the top a bit. I thought about just making the head opening larger, but then I realized a toddlers head is much larger than their shoulders - proportionally. The opening would have had to be too large. I decided to line the neck and front opening (I added) and make buttons in the front. It was pretty easy and I think they look great! The bottoms are simple pajama pants - just like adults! So easy and so comfy to wear.
My son trying them on. He loved the "birds" on the fabric.
A second pair.
My son called these the "music" ones. I guess he knows what a music note is. It's funny the things kids catch on to and remember.