To begin with, create a feather template you're happy with and use it to cut out your leather. Look for feather patterns online, or draw your own. We liked using sharp scissors for cutting, but you can also use a x-acto knife if you prefer.
The next step is to punch a hole in the top of the feather. We used a leather punch for this and it worked really well.
Apply gold leaf adhesive to the bottom of the leather feather with a small paint brush, creating a spotty coat so that some of the leather will still show through. Dap off any excess with a paper towel. Wait for it to set, according to the manufactures directions, and then apply gold leaf. This step is optional. You can also use silver leaf, or rose gold leaf for a different look. Or leave the leaf off all together.
Using a sewing machine and coordinating thread (or contrasting for a different look), stitch a line down and back up the middle of the feather. Pull threads through from the front to the back and tie off the ends on the back to finish.
Cut fringe along the side of the feather with sharp scissors, stopping short of your stitch line, on each side. Try to angle the slits downward to look like a real feather.
Using an open jump ring, add some pieces of gold chain in varying lengths to create a tassel at the top of your feather. Next add a long chain to the top jump ring as a necklace and then carefully close the necklace with small jewelry pliers.