When I first got a Tarptent, I painted the suggested sealant stripes on the floor, but my Thermarest still flew all over the tent every time I turned over. I contacted Henry Shires, who suggested painting stripes on the bottom of the Thermarest. It worked! I like 300winmag's idea of the dots--easier to do.

The OP might want to do a search; there have been several threads about slippery sleeping pads lately. Be sure to change the time parameter to longer than 1 week.