I’ve used the little 1/80 and 1/100 oz jigheads to sucessfully catch trout, brim, bass, and crappie but I wanted an even smaller jig. So, I took some little size 12 mustad jighooks, some translucent glass beads, lead or copper wire and created some even smaller than the 1/140 oz jigheads you can purchase. Putting some orange or red thread under the translucent bead covered with super glue gives the appearance of a red eye, or orange.  Putting some copper wire or .15 lead wire around the shank adds some weight to the little jig. The body is merely the remaining marabou from the tail, twisted and palmered on the hook shank.  A simple fly but deadly .  Try em; you’ll like em.