I'm with you crafter2243. I find a denser design works better and I use wss on top and bottom this worked a dream on the teatowels I did today!
I would not use red-work design since most of them have thin lines that might disappear in the waffle even when you use a topping. A friend of mine used tulle on top of her towel to stop it from getting lost in the nap and it tore off real nice. Curious what other have as an answer.
Thank-you for mentioning the tulle - I was worried about using a denser design as I thought it might turn out very uneven and bumpy.