I just found this tutorial but his one makes a smaller version, but you could enlarge it to make it bigger
I have been reading that the mug rugs are 6 x 9, 5 x 10 etc.
http://www.articlesfactory.com/artic...-mug-rugs.html
another pattern in pdf (* 8 pages to print) and you could make it bigger but this give us the general idea and also a cute way to applique and make cute towels
http://4h.wsu.edu/clothing/quick_projects/MugMats.pdf