Here's coaster pattern - you could just make it bigger for a hot pad:
http://allsorts.typepad.com/allsorts/2006/11/crisscross_coas.html/
If you can't get to it that way, let me know. It sorta resembles the top of a box you have closed by laying down the flaps in order & the last one is tucked under the first.You can do it with all one color, two or 4 colors. Really easy.
ashiecat1954