The cork trivets that I purchased from World Market seemed kind of thin to me, so I came up with the idea of stacking two of them and upholstering the top one with fabric that I had left over from other projects.
I started by tracing around the trivet and then around something a bit bigger than the trivet (in this case, a plastic plate with a Tonka Truck picture in the middle of it).
I then cut around the larger circle and cut triangles out around the larger circle, being careful not to cut all the way to the smaller circle. It is important to leave a space equal to the thickness of the trivet, between the point of each triangle and the smaller circle.
I used Mod Podge, applied with a foam sponge brush to attach the fabric to the trivet.
I, also, used the Mod Podge to attach two cork trivets to each other.
After the Mod Podge was thoroughly dry (overnight), I sprayed the fabric with 3 applications of semi-gloss clear coat.
The finished trivets: