Another Towel

I gave myself a challenge a few years ago when I painted on onion still life with a towel. It turned out to be a royal pain in my ass but I was so happy with the end result that I challenged myself once more. In 2008 I completed a small still life of an heirloom tomato wrapped in a colorful towel. That was the hardest thing I had done in terms of creating texture that was believable. I set to top myself once more last year. Since then I've been slowly working on this still life, perhaps the slow pace was preventing me from working on the towel, which covers more space in this painting.
I have been so afraid of the time and pain I would invest in this piece that I keep setting it aside, and if I do work on it, it's to "fine tune" the onions and tomato, but how much fine tuning can I do?
I had no choice and I had to start working on the towel. By now I have thought about how I'm going to approach it but after thinking about it for a year my mind has gone blank and I don't know what to do. I try to remember how is it that I worked on the last towel, but as I remember it that was also another battle!
I have been adding dots, blobs, color upon color trying not to get an even pattern. The texture of the towel needs to bee more random, I think, for it to look right.
So far I don't know if I'm succeeding, all I know is that I'm chiseling away hoping of the best.