So you find a hole in a piece of wood, or other similar project. Perhaps you drilled a hole in the wrong spot and you just want to patch it up
Try this:
You'll need normal every day Baking Soda and some super glue. If the hole is not too shallow, pour a little baking soda into the recess and then add a couple drops of super glue. In about 2-3 seconds you will have a super hard, epoxy like plug that is something like 3-4 times harder than the superglue would normally dry to.
If the hole is any deeper than maybe 3/8", then fill it in layers and steps. The super glue will actually dry and harden before it can soak all the way through the baking soda, leaving just powder at the bottom
Finish by sanding off and smoothing