When I was younger, I used to "pick" nightcrawlers the night before a fishing trip. Just give your lawn a good soaking with a sprinkler, during the evening. Then, after dark, go out with a flashlight. The worms will be out in mass!
But, you either have to be really quick once you spot them. Otherwise, they will dart back into their holes. The best thing to do, is put a red lens or cover over the light beam. And just walk lightly. They can sense a light and / or the vibration of your steps.
On a "good lawn", you should be able to catch about 1 -2 dozen in a half hour to and hour.
Then, you hit the sack and dream of all of the fishing fun you will have the next morning!