At present, my speaker cables are routed behind a bookcase, from amp to speaker, so they do not touch the ground at all.
To be honest, I don't notice any improvement etc, but perhaps since they are touching something, it nullifies any advantage of not touching the floor?
Not played around with any cable risers in the past, but I am not knocking the idea either - shoot, I never would have believed the difference that isolating my old DAC made either...