Place a blanket inside a crate that is just big enough for your dog to stand up and turn around in. Add a shirt or other item that smells like you to make the crate comfortable.
Show your dog that you have yummy treats and toss a handful in the crate. Praise him for entering. Repeat this several times until your dog is comfortably running inside to wait for the treats.
Show your dog a bone or toy stuffed with his or her favorite treat. Toss the bone inside the crate and close the door with your dog on the outside. Allow them to scratch at the crate, bark and whine. You want your dog to be very excited to run INTO the crate. After 1-2 minutes, let them in the crate and close the door while they chew on the bone or treat filled toy. Let him/her out when they are finished with the bone. Repeat this a few times until your dog is seeking out their crate and asking to go in :).
If a crate is too large, they will soil the bedding. The crate is not for food and water. The crate is for creating the feeling of a “den” that a dog would make for themselves.