I found the pattern on Ravelry, and I'm sharing it with you here. I made some changes though, switching to a half double crochet in row 5, and then I used a puff stitch and chained one and made another puff stitch in the same stitch, chained one, skipped a stitch and repeated around in row 6. I couldn't make row six work, maybe due to my tension, or perhaps I miscounted somewhere, so I did my own thing.
They look cute and I'm happy with the result, but I won't be hooking these up again any time soon unless I learn some trick to loosen up my tension. I might try other coaster patterns however. We'll see what I create next! I'm undecided at the moment, so stay tuned.