They have all been crate trained at some point.

I do it by leaving the crate open and leaving some treats int he back of it when they aren't looking, so they find them in there when they go in. Then I put something like a stuffed kong inside and shut the door with the pup on the outside, so pup wants to get in. Once pup is in I feed treats through the closed door and gradually build up the time the pup is left.

However, despite being crate trained, none of them currently use a crate at home,a nd the older one hasn't been in a crate for yonks. The younger two travel in a crate in the car if they are on their own, but otherwise no longer use a crate at home now they are toilet trained.

I find it beneficial to help with toilet training, and as I prefer to crate them for benching at shows if possible. otherwise, i probably wouldn't feel the need to have crate trained/using adults, but i don't leave them really, so never get problems with chewing etc.