Walk slow and keep your eyes peeled. Many times you'll hear something rustling a plum thicket or briar patch, and if you look closely a lot of times it's a covey trying to run away. Also, listen closely after you bust a covey and they start calling back and forth. The whistle is different from the "bob white" call you hear a lot, and I've used it a lot to find singles and small groups of birds. The hardest part of not using a bird dog isn't finding birds to shoot (my beagle does that on a regular basis), it's finding birds that have been shot. You can walk back and forth for a long time right where you saw a bird go down, and if he wasn't deader than a hammer when he hit the ground...well, good luck finding him. That's why I don't bird hunt much right now. I don't have a bird dog, and I lost too many birds that should have been found. Hopefully by next season I'll have a good bird dog.