I had twin pygmies born during a freak april snowstorm last year and needed the coats in a hurry.
I had the coats already cut out. I used several layers of fleece and sewed the fronts shut. But I still needed a band to keep them on.
I used soft fleece horse leg wraps that I had sitting around here. They already had the velcro on the end and I just cut it to the length I needed. I didn't sew them to the blankets, just wrapped it around the belly over the coat and it worked great. It would only take a minute to sew them onto the blanket, but the babies grow so fast that I left them seperate so I could use them with other blankets.
For people that prefer a pattern their is a dog coat pattern that works well for goats too.
I used up old jeans to make goat coats one year. They hold up great and are very warm. You can also use an old blanket for filling instead of buying fiber fill like for a quilt. I just used a dog coat pattern that I had and modified it a little.
One of our favorite quilts was one I made out of denim. They are warm and so easy to clean. We never worry about ruining it and take it everywhere. Camping, picnicing, the beach....
I bought mine from Walmart, they're dog coats. They are quilted and pretty much like something you'd put on a horse, just a lot smaller! They have adjustable belly bands and fronts. I paid $6 a piece.