-at least a square foot of fabric
-sharp cutting shears
-Large crochet hook (I used size N)
-a little patch of felt
-needle and thread
Lay out the fabric and start cutting from one end to the other in small strips, but DON'T cut all the way down. Don't separate the strip from the body of the fabric. Just go down and leave about an inch of uncut fabric and turn back around and start cutting back. Do this so that the entire piece of fabric turns into long strip! If you're confused, refer to the picture, or comment and I can post a diagram.
Ball up the fabric strip! If you don't know how to ball yarn, now is the time to learn! Wrap a strip around your index finger and middle finger and make a little wad, then take it off of your fingers and wrap it perpendicularly, so that it looks like a little bow. Then just keep wrapping and making it look more and more circular! If my instructions have caused havoc, check out youtube for some tutorials!
Start crocheting! If you can't do this then you need to hit up your grandma or youtube again and watch some tutorials. It's so easy to crochet in a circle with some practice you'll be a pro! I personally crochet circles using the "magic circle" method. It works beautifully!
Make your coaster as big as you want then sew in the ends and grab that felt! Cut out a felt circle for the back that's a little smaller than the actual coaster.
Get your needle and thread out and sew the felt circle on! And you have your cute and easy coaster!