How do I fix the whole for screwing in a chair leg?

you might add some toothpicks to make it fight tighter and add a litle glu

I use golf tees to fill oversize screw holes. Coat the golf tee with wood glue, insert it in the hole, let the glue set, cut off any part of the golf tee sticking out, drill a new hole for the screw.

Ask your meat cutter if he has any wooden meat skewers. They work great.

I've successfully used the golf tee trick, and I can also recommend that.

In the plumbing department of most stores, you can find a little tube of 2 part epoxy putty. Get white if you can find it, but grey will also work. Mix according to the directions and fill the hole. Let it sit for 24 hours. It will be nice and hard and you can just drill a new hole, then dot a little stain if needed to color match your repaired item.

Using Jane's method, I would be a little skeptical that depending on the epoxy, it may chip when screwing in the new wood screw. I might suggest mixing the slow setting epoxy with sawdust...saturating the sawdust completely, then forcing it into the hole with something small eg. a nail making sure the mixture fills the hole from top to bottom. When set, drill a hole in the center of the "set up" epoxy mixture filled hole. Use a sharp drill approximately 1/2 the diameter of the screw. The depth of the hole should be about the length of the screw. Done properly it should hold til the cows come home!!!!!! OR......or if you want something that will hold until the republicans agree with the democrats....or vice versa, use Jane's method. Clean out any debris out of the hole where the screw was. Then with the two pieces of "whatever" clamped into the correct position, mix the epoxy thoroughly. Then force the epoxy into the hole with a nail or wood matchstick so that the epoxy fills the hole from top to bottom. Then cover the new screw with a light layer of the epoxy. Place the screw in the epoxy filled hole and push it into the hole completely. Make sure that whatever the screw is holding whatever together, that it is in the CORRECT position/alignment because when that epoxy dries, it will take an act of congress to separate the two parts. Clean off any excess epoxy around the repaired area. Good luck. Best to wear some rubber gloves - getting epoxy on the fingers is a mess...

Toothpicks and/or golf tees in the hole with wood glue, as mentioned above. I have old, solid wood heavy paneled interior doors. I stripped and redid all of them last year. Many of the hinges were loose (holes too big) and that's how I fixed them and they work perfectly, none of them have loosened up again. Epoxy would worry me, you would have an impossible time trying to get that screw out later if you had too. You could put in epoxy and then let it dry, it might chip though. By the way, leave the toothpicks sticking out. When you drill the new hole it makes it easier, stops the drill bit sliding sideways. You can just pinch the exposed ends of afterwards, with bullnose pliers or a stanley knife.