I had these coasters that I bought years ago at Ross and they just weren't jiving with me anymore. Lucky for me I also had some leftover fabric, a jar of modge podge, and a foam brush. Sounds like a recipe for new coasters to me!
I just laid the coaster on top of my fabric and traced it lightly with a pen. Then I cut it out and applied a layer of modge podge to the coaster, then applied the fabric, then applied more modge podge to the top of the fabric. I just let them dry on the counter and within a few hours we had some "new" coasters!