The first and most crucial factor to consider when buying a dog crate is the size of the dog itself. You must make sure that the top of the cage is at least 4 inches higher than your dog.
Well-designed dog crates have other useful features like two large doors, a removable pee tray, a collapsible design for easy transportation, and durable paint. Also, it's always better to get a wire cage rather than a plastic one, as it's much more durable.