Crate Training is a kindness

All training starts with taking advantage of your dog’s natural inclinations to reinforce the behavior you want. The only place your dog will not, by nature, mess, is its sleeping place. Crate training works with your dog’s instinct - he never has the opportunity to be “bad.”
Crate training is fairly intense for you. The rule is: if you are not actively paying attention to your dog, your dog is in the crate. Period. Even if you’re in the same room. If you’re not watching your puppy, it’s in the crate. If you think “caging” your dog is cruel, get over it. It’s worse for your dog not to know the rules of the house.
Crate training is not an excuse to ignore your dog for hours at a time. A puppy cannot go more than a couple of hours during the day without a “bathroom break.” If your dog learns to mess in its crate the behavior is very difficult to correct. It’s one of the biggest challenges when adopting strays or rescues from shelters. It can be done, but requires patience and dedication.
Dogs should be taken out at regular intervals; after meals, after naps and after play sessions. And “business” walks are not playtime. Put the collar and leash on, take the dog to a specific spot you want it to use for its toilet area, give your dog a command “go potty.” If it does, reward it with praise and cookies, say “good go potty.” Forget about public embarrassment. If you’re easily embarrassed, don’t get a dog. Of course you can use any words you want - a friend of ours used “hit it” with her dogs. She just had to be careful not to use the phrase under other circumstances.
Your puppy should also sleep in the crate, ideally in your bedroom. Dogs are social animals, they need to know their “pack” or family, is close by. If the dog wakes you in the night, take it out on leash. Give it 10 minutes to “do its business,” go back in, pop him in his crate, say goodnight and go back to bed. Don’t let the dog out by itself, even in a fenced yard. Again, this isn’t playtime.
As your dog learns what’s expected of him, the next phase is to keep the dog on leash, out of the cage. Tie the leash around a belt loop so that you can go about your daily routine with both hands free. Keep one eye on the dog. When you see his “gotta go” signals, drop what you’re doing and go. Some people are successful in hanging a bell on the doorknob. They ring the bell whenever they take the dog out. The dog learns, over time, to ring the bell when it has to go. Others teach their dogs to “speak” as a signal to go out.
Our dogs are always crated when we leave the house. At this point, they see us reaching for their crate toys (which we stuff with a little peanut butter or kibble) and run for their crates. We don’t necessarily even lock the crates, but they are available to the dogs at all times. It’s their “room,” a safe place they can always go to.
Just a note of caution and safety: never leave a collar or harness on your dog in the crate. It can get caught and cause problems.