It's a pretty jacket. If you are nervous about embroidering on the jacket itself, make the designs you choose free standing and stitch them on.
I embroidered a design on tulle to try out on the neck line of dress. the tulle worked to keep the design together but still able to see how design would look and where it look best. Good luck. Cheri
Here's a link to some inspiration. Hugs. Nan W
How about a 4x4 design repeated down one side in one or more bright colors.