Crickets are best caught by hand, but if thats not an option, and you have a spot with lots of crickets, there are a few options that work pretty well. You can just throw down a piece of wood on top of the grass, go back the next morning, and pick up the board and catch the crickets,
Or dig a hole big enough to fit a 1 gallon ice cream tub in, pack the dirt in around it, and lay a piece of wood over it, you should have crickets in the bucket the next day,
Or get some cardboard egg flats, and lay them down and cover with leafs.
I have never used bait, the best bait for crickets is shelter.