I've made two...one years ago from a pattern specifically meant for a quilted jacket. It was tougher than I thought though.
The second I did the sweatshirt method where you take a sweatshirt one size too large and cut it apart at the seams. Then you have the basic pattern pieces pretty much in the right shape. I made rows of piecing and then did the stitch and flip method to cover the pieces. Once they were fully covered, I sewed the edges and trimmed them before quilting them and then sewing them back together. Then I did have to do a bit of fitting to get it to fit well. I did NOT use extra batting as the fleece gave it plenty of body I did bind around the whole outside and mine doesn't have a zipper/buttons or any type of closure.