I've been busily filling the background of the quilt with little feathers - the longest wouldn't be much more than about 3in, most are around 1 1/2 - 2in, and some are as tiny as 3/8in. The overall effect is better than I could have hoped - it was definitely the right choice and actually pretty quick, too (although that's partly because the quilt is only about39in square).
I've been marking guidelines for each plume of feathers - a rough spine and then the boundary for where the feather tips will reach. It's been working quite well and giving my nice, relatively even, shapes.
I've also been marking a curve inside the tighter curves to help me position and shape the shorter feathers smoothly, as this is one area I tend to struggle. This has been really effective, and I'm much happier with the feathers on the inside curves; they're a much better shape than usual and flow nicely.
There are only a couple more plumes to go, then some smaller spaces I need to tuck some feathers into as well. The pink thread is working really nicely to make the background a bit pinker, too.