It is normally easy to train a puppy to a crate providing you do it correctly. This starts with picking the correct crate as there are many types and sizes to choose from.
I always recommend picking a crate size that the puppy will grow into. Pick a size that will fit your dog breed at maturity. Next, choose a crate that is durable like metal or good quality plastic as they are less likely to chew on them.
An added benefit to crate training your pup is that you can incorporate potting training to go along with it. Typically a dog will not soil where they are confined for a period of time. Therefore with a few dog training techniques, you and your pup will benefit twofold.
Once you have brought the crate home it is time to introduce it to your pup. First, put a doggy blanket or bed in the crate for comfort along with a couple of chew toys. Then leave the door open so your pup can go in and explore this newfound den.
Never close the door for the first couple of days while your pup learns to appreciate this space. The idea is to get him or her use to a quiet place where they can chew their toy and sleep without being interrupted.
An extremely important part of this training is to develop a schedule where you regularly take your pup outside to go to the bathroom. Dogs by nature are creatures of habit and fit into routines every easily. It is important for you the dog owner to develop this routine every few hours and stick with it especially in the beginning to avoid bad habits from developing.