MeatHead, we have fished for the crawfish in 11-mile res for years. I usually wait until June since earlier in the year, the females have their egg-sacks and I don't want to take them while they spawn. But, later in the summer we have the best luck at night usually late and use chicken livers, and chicken necks on strings or traps and have been able to catch a cooler full most nights. Now, we did notice this last year 08, that there didn't seem to be "as many" crawfish as in past years, so maybe they follow some type of up and down cycle. We usually boil them up Cajun style and the family loves them. Another nice thing is, that 11-mile is basically clean water, so you don't have to flush them out per say.
You can set out traps in many lakes, I did it down at McPhee and caught some good numbers as well as size. We had a private lake that we would set the traps out on and catch enough for a party. They were tasty. Just a little bait in the trap and they crawl in. Much faster than trying to catch them one at a time using a pole and hoping they hold on as you reel them in.
I use to take my daughter and a few of her friends and have a crawfish tournament, see who can catch the most, and the winner gets a few dollars. The kids love the competition and we usually would end up with 20-25 of them. JED