I'm always running out of paint stirrers when doing paint or epoxy work so I recently bought a big package of construction shims. They're pretty crummy wood, but they work just fine as stirrers and are cheap.
You could ask for (or grab) a handful of free paint stirrers on your way past the paint department at your local big box store. After a few visits, you should have all the paint stirrers you'll ever need.