To use a Thingamabobbber, first decide how far above the fly you wish to have it. Then attach the Thingamabobber. To attach a Thingamabobber, take a portion of the leader and pinch it together to make a small loop. Pass the loop through the grommet of the Thingamabobber and then pass the body of the Thingamabobber through the loop. Pull on both ends of the leader to seat it. When a fish strikes the nymph, the Thingamabobber will stop, move, or be pulled under.