Simply empty out some cans of your choice and rinse them out with water. Then take some tin snips and very carefully cut off the top and bottom of the can. This can be a bit tricky. Be sure to save as much of the flat part of the side of the can so that you can get a nice size square for your coasters. Then cut down the seam of the can. Most cans will have a definite seam on the side…usually by the ingredient list.
Then take some Silicone and put a good amount on the back of the square. Then attached them to some simple white tiles that measured 4 by 4 inches. Home Depot has them in the tile aisle less than 50 cents each . Flatten and rub the tin square so that it is securely attached. Wipe any excess Silicone off the top of the tile with a damp warm cloth.
Then set a paper towel on the top of it and lay a pile of books on it and let them dry over night! The next day take a small paint brush and paint some glossy varnish over the top of it to seal it all off so that the edges dont peel up and to protect the edges from poking or scratching any users of the coasters.
Then simply place some felt pads on the bottom of the coasters to protect your table top from getting scratched!
( this awesome idea was borrowed from The Idea Room )