What to look for
Size: stand up, turn around, lie down. That is the whole sizing rule. No bigger for a puppy in training: too much space and they will potty in one corner and sleep in the other. Many wire crates come with a divider panel so one crate grows with the puppy.
Wire crates: great airflow and visibility, and they fold flat for travel or storage. Plastic airline-style crates: cozier and more den-like, better for anxious dogs, and they double as car crates.
Two doors are handy for flexible placement in the house and the car. A removable tray underneath makes cleanup after accidents much easier.
Think about placement. Put the crate where the family actually spends time, not in a distant laundry room. Dogs are social sleepers; a crate in the living room gets used, a crate in isolation gets protested. Covering three sides with a light blanket makes it den-like, but leave the front open for airflow.
Bedding: keep it simple at first. A flat crate mat or an old towel is enough for a puppy who might chew or potty on anything plush. Upgrade to the cozy bed once the puppy is reliable. Avoid anything with stuffing for the first few months.
What to avoid
A crate that is far too big "so they have room." Extra room is the enemy of housetraining. Use the divider until the puppy is reliable.
Using the crate as punishment. The crate must predict good things, or the dog will fight going in every time. Never shove a dog in the crate when you are angry.
Crating a puppy all day. Young puppies need a potty break every few hours. The crate is for naps and short absences, not storage.
Skipping the introduction. The fastest way to a dog who hates the crate is to lock them in on day one. Play crate games first: toss treats inside and let the dog walk in and out freely, feed meals just inside the doorway and then deeper in over several days. The door closes for seconds, then minutes. Most dogs are happily napping in there within a week.
Letting the puppy "cry it out" for hours. Some fussing in the first nights is normal, but prolonged panicked crying teaches the puppy that the crate is where bad things happen. If crying escalates instead of fading within 10 to 15 minutes, you moved too fast. Back up a step.
Our take
A wire crate with a divider panel covers most puppies from 8 weeks to adulthood. Feed meals in it, toss treats in randomly, and never force the dog inside. The crate sells itself when good things keep happening in there.
One last thing: the crate is a tool for management and rest, not a substitute for exercise and training. A puppy who has played, trained, and pottied will nap happily. A puppy who has done none of those things will protest, and no crate on earth fixes that.
When the puppy is reliably housetrained and settles on their own, start leaving the crate door open. Many dogs keep using it voluntarily for years. That is how you know you did it right.