I have made a few feathers from small angle iron, 1/8 by 3/4 and 1 inch. I cut both sides of one end to a gradual arcing taper and then flatten it out without flattening the V where the sides meet, and cut a short taper on the other end of a predetermined length for the quill end and then use this feather or leaf block to get the veins or veining.
its just a center stem ground in the center with a chamfer on one end and then vein marks are ground in lightly with the flat of a very coarse grinding wheel as shown. The V part that is left on the angle is put down into the groove and the top worked, I generally use a flatter on top to strike the hot piece evenly.