I use grip tape under my heels to stop my feet slipping when driving, this kind of stuff
http://www.ebay.co.uk/itm/24mm-x-5m-Anti-Slip-Tape-High-Grip-Non-Slip-Safety-Abrasive-Self-Adhesive-Black-/261886347852?var=&hash=item3cf9a48a4c:m:mC2IhdaFAUFxZ_lHWeldGfQ
Also have it on the pedal surfaces.
Its been in two years now and still wearing well. If it fades I can always rip it out.
I use it under where both heels go , and further back on the left clutch foot side as a 'rest'. Also as I dont run with the carpets in , I have strips where the passenger steps in to avoid spills.
