I made these coaster sets for my friends a few years ago and they loved them. Everyone still has them out in their homes and uses them when we have wine nights. Not only are they super cute and customizable, but fully functional and pretty inexpensive to make.
You will need:
4 ceramic tiles (I used 4.25" square tiles from Home Depot, they were less than $1 each)
Scrapbook paper in any pattern or color you choose (can also use newspaper or magazine cutouts to make a collage - be creative!)
Felt (No need to spend a lot, got mine from the remnants bin at Jo-Ann Fabrics)
Matte spray paint in Clear
Glue or Permanent Spray Adhesive
Step 1: Measure and cut the scrapbook paper into 4 squares. I cut mine to 4" because I like the white border, but if you don't just cut to fit the tile exactly.
Step 2: Lay the felt out and trace around a clean tile 4 times. Cut inside the line. Set aside for later.
Step 3: Put a thin coat of Mod Podge on the back of a paper square and affix to a clean tile. You will have a little time to adjust it to get it straight before the Mod Podge sets. Rub out any air bubbles with the heel of your hand. Do the same for the other 3. Give it a few minutes to set completely.
Step 4: Apply a coat of Mod Podge to the tile and paper. Make sure all of the edges of the paper are sealed down to the tile. If there are any air bubbles, you can just smooth them out with your finger. Allow to dry completely. I like to apply two coats, but that's optional.
Step 5: Once the Mod Podge is totally dry, spray bottom of coasters with clear spray paint. Once dry enough to handle (usually about an hour), spray the tops and sides. Allow to dry fully (I recommend 24 hours). This will seal the coasters and make them waterproof.
Step 6: After the spray paint is completely dry, glue or spray mount the felt to the bottom of the coasters. I just used regular old Elmer's glue for this and applied a thin coat to the edge of the tile and a bit in the middle to secure it. Stay as close to the edge as possible so the felt does not separate from the tile. Remove any excess felt around the edges with an X-acto.
Step 7: Make some drinks and enjoy. Cheers!