So you've got the clicker timing down? That's a good thing.
The thing about heeling is it's hard to reward dogs while they are actually performing the behavior since we're moving, so we tend to stop to treat the dog. That doesn't really tell the dog that being in heel position as you walk along is what gets rewarded, so they pay attention to the stopping more than to what they need to do in heel. So.... a couple things to try.
One is get something really easy to eat and give on the run treats (I like weiner cut into TINY pieces) and learn to get that treat into your dog on the move. Easier with my size of dog than with a cocker I know. You can try things like putting a dollop of peanut butter on the end of a wooden spoon. You can keep the spoon out of sight in your right hand and shwoop it down in front of the dog's mouth to reward her. I know it sounds dorky but lots of OB people with little papillions and other toy breeds use this method and it works well.
Practice lots at home and build number of steps heeling gradually. Then practice on your driveway , in your yard and build up to more difficult places gradually as your dog shows you she's ready.
What do you do when your dog forges?
I like the method where the instant they get too far ahead, you mark the behavior with a phrase like "oh! tooo baaad" stop and get them back into heel position. When they're back in position and preferably looking at you, you say heel and off you go.
(Of course the first step before working on heeling is teaching them to get into heel position on cue. My cue is "get in" and was taught initially by luring with a treat and feeding in position) Obviously the dog doesn't get a treat for 'getting in' if it was forging that caused you to cue the behavior, so you can see why it's important to have that one down first.
The biggest thing I see people in beginning OB classes do poorly with heeling is they walk too slow and don't have good timing to reward the dog. Walking slowly is boring, sets the dog up to ignore you, forge and find something more interesting to do. If your timing is late you end up rewarding the dog for being out of heel position and it doesn't work well.
People get a bit overwhelmed and can't seem to walk, watch the dog, remember their marker phrase, click etc. I was no different starting out. I can barely walk and chew gum, so holding a leash, watching the dog and trying to click was too much for me
I ditched the clicker and just learned to walk fast and talk nonstop to my dog telling him how great he was and shovel food in his mouth as we went and stopping and saying "too bad. get in" when he forged.
That's part of why practice at home is great. You can just relax talk to your dog the whole time she's in heel position you're saying "woohooo! look at YOU! GOOOD DOG!" etc and keeping the dogs interest. If you walk into a wall because you're looking at your dog nobody has to know
The other method I LOVE is called "choose to heel". It works well and is EASY PEASY and FUN. 'Choose to heel' is where you go someplace enclosed and preferably boring like your training facility at open matt time, an empty tennis court etc I used an outdoor hockey rink in summer. Any largish, emtyish room will do.
You start walking in a counter clockwise big circle around the room, say nothing to the dog, don't look at the dog, just leave the dog to explore and do what they want. You walk with a purpose like you're on a mission. Eventually your dog will go "what the heck is she doing?" and come over to investigate. Your left side is exposed, your right side is hopefully near a wall or barrier so the dog really only has your left side to approach. Don't look at the dog or say anything and the INSTANT the dog is in heel postion you CLICK and toss a treat away. The instant the dog is in heel position CLICK and toss the treat away so the dog has to leave your side to get it. Make the treat BIG, smelly and easy to find, like a hunk of cheese or meat. The dogs are usually VERY interested in coming back to get some more cheese and curious as to why you're walking around like a cray woman and flinging cheese
So you keep walking and repeat - the instant they are in position you click and toss your cheese.
I love this one because you get the dog performing the desired behavior, which is really not that fun for dogs, with huge enthusiasm. They don't HAVE to heel they WANT to heel and it has become a fun game.
The only difficulty with choose to heel is scouting out a good location that is enclosed so that you can safely ignore your dog. If it's a boring place that makes the process faster too.
My dogs will come into heel position when we are on a hike when they are quite free to be off sniffing and loook up at me like "check me out. I'm in heel position. got anything for me?" I've gotten to the point with my bc where I'm saying "go play silly" because he keeps coming back to heel trying to get treats and show off. heh heh
edited for scary number of typos and spelling errors!