They sell some non-slip plastic self adhesive stuff at good boat supply places that comes in a couple of colors,looks great, and lasts excellent- used it on a couple of slick when wet places on the wrecker truck- works great and has put up w a whole lot for years and still there looking good................
comes in rolls-but if i recall right its not super cheap-but what good is?......[this stuff made for high sun and enviornment exposed boat decks-not skateboards]