A lot of the more competitive trainers are now using perch work to teach the dog "rear end awareness". It basically teaches the dogs they have control over their back legs. After that there are several ways to go about teaching a close heel. You can use your hand as a target at first and then switch it to a hand signal. I strongly recommend working on eye-to-eye focus before you get into the actual "heeling" part. Focus is important here and your dog should be looking up, concentrating on you. You can put a "watch me" command on it and/or teach it as an automatic. Chaplin knows watch me but we also work regularly on having him naturally looking up at me without the cue. This exercise, however, can really effect other parts of training like free-shaping. Chaplin and I tried to do some and it took 13 minutes just for him to look at the box for more than one second because he's been taught focusing on me is the "best thing in the world". But if you aren't doing free shaping and sometimes nosework (it really depends on your dogs breed for nosework focus) it shouldn't be much of a problem. Basically you'll click for any eye movement in your direction at first. Then click for eye to eye contact, etc. Do this every day for a few repetitions in various places. Start with low distraction and work your way up, you'll notice your pup gradually watching you more often without being add. Feel free to add a cue. Make sure you always HIDE the treat in one of your hands, dogs are creatures of habit. If they see you constantly reaching for treats in your pocket they'll stop focusing on you whenever they think they're going to be rewarded. Instead make the treat appear from your eyes in a way. Bring your hand up and lower it from in between your eyes so that's "where it's coming from."
I'm going to post a few videos for you. The first is one of my favorite competition heels, the dog looks happy and has a great prance going, the turns could be a little bit tigther and crisper but it's good to look into the focus you'll need from the dog; so it's not the *best* comp heel I've seen but this one happens to bring more joy to me and it also has some nice retrieves. The second one is kikopup's rear end awareness, it also instructs you on how to make the dog understand to keep by your side. The third is another version of perch work that leads into a heel.
I can't find the last perchwork video I was referring to but I'll add it when I do.
Down the line you'll want to work on "swing" and "place".