http://featheredfibers.wordpress.com...hand-feathers/
Not sure if this link answers your question. I also learned through stencils. I drew the design on muslin with an ink pen for practice. Over and over and over. Once you practice practice practice, hopefully you will get comfortable doing them and you may end up with your own technique. My feathers have parts of the plume and the stem with backtracking. I am now used to the look, as some areas are more prominent than others with the double stitching, and most areas do not have it. When the feather is done, I think the double stitching (backtracking) really stands out and adds to the design. But not always. I too would love to be able to sew these things without the backtracking. To get the look of single stitching, I stop my machine, back stitch 2 stitches, cut the threads, and move to the next area. Works and looks just fine to me.
Leah Day is terrific also. So many designs, so much talent.