Just Dub It

Standard tarpon fly with a dubbed collar of racoon hair.
Step 1: Tie in a loop with the thread at the desired location on the hook shank.
Step 2: When the thread loop is tied to the shank, hang the dubbing tool from the bottom of it so the two legs of thread are separated.
Step 3: Carefully load your fibers of choice into the loop. Once you have all of the material inside the loop, begin twisting the tool to interlock the fibers into the thread.
Step 4: When the loop is twisted tight, the fibers take on a whole new appearance and can be wrapped around the shank just as you would palmer a hackle. After each wrap, make sure to pull the fibers back. Doing so gives the fly an attractive appearance and also prevents overwrapping.