Weezer is right on about hunting the edges. Also try some overgrown fence lines, these are excellent when the temp drops. When you get to the end of your walk stop about 20 ft from the edge and take a few minutes to talk with your buddies, this is a good way to make roosters nervous and to flush. In my experience you will spend a lot of time walking w/o dogs, but it will pay off. Invest in a good pair of boots and don't give up.