Nightcrawlers are easy.Dont use the chemicals or soap or shockers it kills them.

Either wait for a rain,or water your lawn.Best when grass is cut short.
Get a flashlight with week batteries or tape a red tailight lens to it.
Wait till an hour or so after dark.Walk slow and softly while watching the ground.Then when you see them test your reflexes.They are fast as lightning sometimes.
If youy fertilize you wont do as good.It kills the worms.Also why there arent as many moles.

I use to store mine in an old wooden box filled with damp moss.Keep in a cool place.Feed them coffee grounds and eggshells,Other kitchen scraps work well also.

They will last a long time like this.Just add to the ones there when you start running low.Doesnt hurt to change the moss once in awhile.

I made a lot of pocket money selling nightcrawlers,when I was a kid.