For smelt, I take the old strip of metal from windshield wipers and cut off the barbs. I cut one end at an angle to make a point and the other end I bend around to form a loop. You can then put the loop of your leader in the metal loop and run it through the mouth of the smelt, along the spine and exit the body just past where the dorsal fin is. Pull the hook so the shank is in the mouth and the bend of the hook is exposed. Then I tie a couple of half hitches around the tail and you are ready to go. I am not sure if it is true, but I think sturgeon do take the bait in head first. Of course, since I bait them this way, and a sturgeon is swimming upstream to my bait, the head is the first thing it encounters.