Being your dog's leader means just that, to guide and lead through life. It has nothing to do with yanking, choking, yelling, hitting or alpha rolling. Our dogs need a leader; after all we put them smack dab in our human world and expect them to deal with it all. They need guidance, they need an education.
If you add a dog to your family you should start reading. Of course you should read a great deal because there are many different directions that advice will come from. If you keep a "do no harm" mindset then you will hopefully know when to move away from "alpha dog" mentality training.
Understanding dogs takes time. It also may take a whole mindset of letting go of what you think you know. The "I have to walk out the door first" or "they have to walk behind me" or "they are pulling to dominate me" need to be tossed. Dogs do what dogs do; they are not out to take over our world; although if we allow them to be the leader, many will. Most don't want to be the leader and if we don't step up and lead they are left vulnerable and shaken.
Learn about dogs if you want to live with dogs. They are highly complicated yet very simple once you figure it all out. Each is as different as we are; but in their own amazing dogness, not human at all.