The first and most important thing to remember
This is most important thing you need to consider when training a dog to do anything. For good or ill, it isn't human. It isn't trying to be human. It doesn't even know what a human is.
The worst thing to happen to dogs psychologically in the past couple of decades is the 'fur baby' cult. It's built on the needs and feelings of people who seek to deny the reality of a dog's nature and package up dogs to be little bundles of emotional putty to fill whatever gaps exist in the owner.
If the dog is your baby both you and the dog have problems.
A dog knows it's a dog. It looks at you as a dog as well and it seeks to find its dog status with you, your real family and all the other dogs in the world.
You can't reason with a dog like you might with a child, you can't blame a dog if it doesn't understand what you are saying. It's just a dog and it will do dog stuff. Your job is to think like a dog and find the way to be understood.
It's up to you to find the best way to communicate
Your body language and your energy have the greatest impact on your communication with your dog. It's never the words you use. It's what those words come to represent in the dog's mind. The same word said with happiness or with anger can carry two different meanings. Dogs will feel your energy first, see your body language second, hear your tone third, and hear the word last (if at all...). Consistency in message delivery makes it easier for a dog to learn and that doesn't mean the same words, it means the same energy.
If you want to teach a new skill, do it one at a time
One dog at a time is the key when teaching something new. In a group, dogs can opt for the lowest common denominator and pick the opposite of what you are trying to teach. If you are working on a new skill for the dog to learn, isolate the trainee and work on the basics with that dog alone. Once you have the basics in place you can use the energy of stable, focussed and trained dogs to reinforce the message. Start with one dog at a time...
Everything you do is teaching your dog something
Dogs are watching you at all times. They know when you are focussed and when you aren't. Be conscious. For example, if you are firm and clear in your instructions to your dogs 99 per cent of the time but vague out when you decide to check your social media, the dog will learn it only has to do the task 99 per cent of the time. The moment the dog feels your attention shift to your phone, they will check out. "I just looked down to check a message and the pups disappeared..." No. You taught the pups that the moment you reach for your phone they are no longer under your control and it's playtime. Be consciously consistent in the messages you send.
Get the result before you pay
Dogs love rewards. They love a snack, a pat, a trip in the vehicle, a toy, work...they love it all. However, you cannot fall into the habit of diminishing the power of that reward by handing it out for nothing. Even worse, don't teach the dog to demand you pay them for nothing. We love our dogs so we tend to hand out affection because our dogs are so awesome. Don't. Affection (and that includes a smiling face as well as pats, feeding, letting them out of a cage or off the chain or leaving them to run around free in the yard) has to come with strings attached. They must work for it. If you get home and go to let the dogs out for a run, make each one sit calmly until you say 'free' or 'out' or whatever word you choose to use for that specific instruction (remember, be consistent). You are rewarding the dog for sitting calmly. When you feed them, make them wait calmly until you say 'yes' or whatever. Again, you aren't feeding them, you are rewarding them for sitting calmly. Don't pat them if they waddle up to you. Pat them when they come up to you and sit. A key tactic here is to catch them doing what you want and reward them. If they are calmly lying on the lawn, give them a pat. You are rewarding calmness again. We all want to pat our dogs but make them work for everything. It keeps them focussed on you and what you want.
Don't reward negative or destructive behaviour
...and don't leave a dog to create its own job description
...and don't leave a dog to create its own job description
...and don't leave a dog to create its own job description
...and don't leave a dog to create its own job description
...and don't leave a dog to create its own job description
If you absent mindedly pat a dog that jumps up on you, you reinforce that this is not only acceptable but sought after behaviour. Reward them for the jobs you choose, not the ones the dog makes up because you're looking at your phone.