I started by shopping in my backyard. Cheapest store ever. I found a fallen log thats diameter was bigger than a cup. A log that has been down for a while is best because they have dried out some. Then I stuck it in my garage for a week to dry out some more because it was raining the day I got it. Pull out your saw and slice your log into about 1/2 inch pieces. Be safe and don't cut any fingers off.
Gather up your supplies.
Cork-I bought mine at Office Max for about $10 in a giant roll. You could also use felt if you have some on hand.
E600 or another strong glue
Grab something round that is a little smaller than your coasters and use it to trace a circle of cork for the bottom of your coaster.
Cut out the cork and glue the cork onto the coaster. Use something heavy on top of the coaster to help keep the cork attached to the wood while the glue dries.
Done! So easy. These would make such a cute neighbor or hostess gift. I would guess they cost less than 25 cents each because of the cork.
Or you can just keep them all to yourself!
