There is no way to use two shed sticks together. Instead, to produce a plain weave you must alternate, first using the shed you can produce with the shed stick, and second, interlacing by hand. You of course have to remove this pick-up stick before you can open the next shed. All around the world, ingenious weavers came up with the same idea, revolutionizing weaving technology. All other loom refinements pale in comparison.
Most tribal weavers use a continuous string to make a series of heddle loops.
Since these can slip and slide and become a tangled, uneven mess, I'll describe my favorite foolproof method for klutzy weavers. First, make a series of identical separate string loops. If you have a total of 60 warps, you will need 30 heddles. You can use them over and over again for future weavings. If you haven't made a pick-up stick, use one of your extra slats, or a ruler.