This was my first DIY project off of Pinterest (surprised?) and I have to say it was simple, cheap, and actually quite fun!
(Ignore the blue line across the top...it's a glare from my TV...)
The other supplies you will need are Mod Podge, small sponge brush, clear waterproofing spray paint, felt, and Tacky Glue (or something similar).
Mod Podge the photos to the tiles.
Evenly cover each photo with Mod Podge. Let dry. Repeat several times.
I found that 3 coats of Mod Podge worked but bear in mind the edges might need a little extra. If you find the edges are bubbling up, which a couple of mine did, just use your finger when it's almost dry to press it down. Problem solved!
I let my tiles dry a couple days while I worked and then sprayed them with a somewhat generous amount of clear spray paint. Let dry completely and repeat.
I found two coats of spray paint worked perfectly but, as you can see, I used the 2x ultra cover. If you are using a basic spray paint you may want to consider an extra coat.
I ordered cheap black felt off of Amazon...worked perfectly. Cut felt into 4x4 squares and use Tacky Glue to adhere it to the backs of the tiles.
Voila! Photo coasters complete and ready to use!