When I realized that doing a simple freehand scroll wasn't enough for the outer border...I decided to do an echo on both sides and this is what I came up with. So happy with the result! Easy too!!
First pass - consider a center section and keep about an inch or less away from both sides of the border (horizontal straight lines in (crude) illustration below), stitching a scroll on the outside of the section and coming back towards the line on the inside. This lets you cross the line to continue instead of sometimes maybe not hitting it.
Third pass (in green)--echo on the outside doing a wave into the open side of the scroll and then just a pivot point at the next large open area.
Curious what people use to create digital illustrations of quilting motifs. Ideas?