We were fortunate to receive good advice when Cub started crawling. For some reason, Cub becoming mobile was kind of disarming to me. He never scooted or army-crawled. He just sat up and crawled one day. I think this made it difficult because we never really eased into him moving around the house--he just kind of did it one day. And suddenly his little boundary (the size of a blanket, maybe?) expanded to our entire house. I explained this to a friend of mine and she encouraged us to begin acquainting Cub with the idea of coming to us when we gave him the command ("Come to Mama" or "Come to Dadda" and motioning for him to come to us with our hands). So, we did that. We would wait until he was distracted and playing with toys, then we would sit down across the room and call his name and gesture for him to come to us. He usually came eagerly, since most babies do at first (I think, anyway), but we kept it up and made it a point to practice him coming to us for a few minutes every day. By the time he started walking, he was used to it.
But, as parents of walkers know, walking is waaaay different than crawling. More speed, more height, more OPPORTUNITY!
So. Our main method now is to allow Cub to walk as much as possible. What I mean is that we allow him to walk, rather than us carrying him, whether it's to the kitchen, to the car, or to the couch to put on his coat. Instead, we go to the place where we would like him to be, and we ask him to come to us. We make sure he can hear us and that we have made eye contact. If he ignores our request and walks the other way, we give him one more chance (making sure that we have made eye contact first). If he disobeys again, he gets disciplined. Every parent disciplines differently, so I'll leave that one open. Usually he comes to us at that point, if he hasn't already. And if he doesn't, then we move on and try the same exercise in a different setting.
Now. My friend brought up a good point that I've seen several parents struggle with--when the toddler thinks it's a game when you ask them to come to you. They giggle and run away, like you're playing chase! It's cute, but not for long (giggling and running into traffic isn't exactly funny). What we've found to work for us is to simply watch our vocabulary. If we're playing chase with Cub, we say, "I'm gonna get you!" as we go after him, rather than "Come here!!" That way, it's clear what we're saying to him. "Come here" (actually, "Come here, please") is reserved as a command only. Does that make sense? That way, Cub knows exactly what we're saying and what our expectations are of him.
Just keep it simple. It's taken me way longer to type this post than it ever takes for us to practice with Cub. We keep it short and simple. And we realize it's always a work in progress. Cub comes to us very well most of the time. Then suddenly, we'll have a day where he looks at us as though we're speaking Pig Latin. But, as with everything else concerning parenting, consistency pays off. A little practice goes a long way, especially if you've already been practicing.
Have a lovely day.