Thanks for the how-to! Great way to add feathers, love it!
As to how to attach it so it can be removed for cleaning... maybe the feathers could be sewn to a stretch lace seam tape (I get them at thrift stores for about 10 cents a pack, sometimes unopened), then hand sew hook and eyes onto the hem of the garment and the seam tape. I am going to try this, I'll post my results once I'm done! :)