I am doing my refeed once weekly to ensure diet compliance even though I'm sure I can get away with once every 2 weeks. It was nice to eat something other than meat and eggs for a day.
I just read that refeeds should be primarily starches instead of glucose/fructose/lactose/other sugars on the leangains website. I also remember on bodybuilding.com there was an article about how you should keep it to mostly starches but start every meal with a small piece of fruit. My first refeed was 50% fruits. I am planning on eating mostly potatoes/sweet potatoes/rice/veggies + 1 pint of blueberries this time around.