Is your dog one of those that heads for the hills the minute they get the chance? If their leash happens to come off; they slip their collar or someone carelessly leaves the front door or gate open? Well, then you have work to do and lots of it. Some dogs are runners, others trigger by movement, many escape just to have fun and then there are the ones who are just too excited to stop and come back. Whatever type you have; they need to be trained to come. Step #1 The way that you train a dog to come is to make the word itself glorious.
Far too often "come" means; the end of game, time to go home, come in because I'm going out etc. etc. So you first need to think about this whole word "come," thing. Does your word "come" have a negative connotation? Think about how you use it; when, where and why? If you arrive at the conclusion that it is indeed negative; then throw it out the window. Pick a new one. You can use any word you like; as long as it is only ever used for good. And that means good in your dogs eyes; not yours. i.e. Calling your dog to come when chewing on the couch would be good for you but not for your dog.
My special word for come is "here" but I might even change it up from that with the next one. It needs to be a word that you can super charge; giving it incomparable positive power. When you say your word you want your dog to jam on their breaks and head home as fast as they can. So that means you have to do the charging; unfortunately you cannot just plug it in and expect it to be all charged up. It is work giving a word such power; you must create the amazing association to it.
Use your word and give delicious treats, use it and feed your dog dinner or breakfast, go for a walk, play ball or frisbee, have a game of tug or invite them into your bed with your word. In the beginning the treats should be the best, save a certain favorite treat like liver or chicken for use with your word. Anything that you could think of that your dog would love; use it as a reward for responding to your new and powerful word.
Now get to work.