Here's a quick tutorial for how to make your own tatting shuttle, if you should ever need one in a hurry :)
They are not quite like the shuttles you buy in a store, but they do work (I have tested them myself). You might need to get used to using a shuttle like this, because it is just a single "blade" and therefore has no bobbin to hold the thread out of the way while you tat. The thread also tends to get caught in the slits on the sides, but you'll get used to that, too, and soon you learn how to avoid it :) These shuttles can be made in card instead of plastic, but they are probably a lot less durable than the plastic ones.
What you'll need:
A plastic lid or box of some sort (thicker than paper, but thin and soft enough to cut with scissors)
A sharp knife
Glue (optional - if you want to glue two pieces together to make a thicker shuttle)
Start with cutting off edges and bends of the plastic you're using - it's easier to cut out the right shapes when you are working with a flat sheet of plastic:
Cut out one or two shapes (or more, depending on how many shuttles you want), in whatever shape or size you prefer :) It's no big deal if the parts are not identical if you intend to glue them together - just hold the pieces together and cut away the edges that stick out.
When you are happy with your shapes, use the hole-punch to make two holes in the shuttle. Exact placement of the holes is not that important, just make sure you make them far enough from the edge to avoid cracking the plastic.
Next, cut slits in the shuttle from the edge to the holes - these are the grooves needed to wind the thread onto the shuttle, so make sure they are wide enough to fit the thread you plan to use :)
If you think the edges are rough, too pointy or uneven, use the knife to round off the corners and smooth out the edges to prevent the thread from catching and fraying when you use the shuttle.
Finally, glue two (or more) pieces together if you want a sturdier shuttle. I found that a single sheet of plastic was strong enough, but thinner sheets might need to be glued together. Wait for the glue to dry completely, cut/scrape away any edges left by the glue, and the shuttle is ready for use :)
Wind some of your favorite thread onto the shuttle and you're good to go :D