I have made a lot of them. I'm not sure I have an photos on this computer. I may have to wait to post photos until I get home. My best advice on pattern is something simple with simple lines. Let your piecing/applique/quilting be the focal point. Don't use batting. You always end up looking fat when you use batting. I use flannel in some jackets, others I piece directly on to a twill backing.
I don't have pics here, but here's a thread on one jacket I made
Spice Market Jacket
And here's another
D9P Jacket
When I make a piece of clothing that's pieced. I cut whatever base fabric I'm going to use (flannel or twill) to shape and then place it on the design wall. I make my blocks and place them on the backing to shape. That way I don't end up making a lot of blocks that are just cut off. I have even use small pieces I cut off the block on one part to fill in a small place on another part. It saves a lot of time and work that way.