Hi LilyBean,
Just keep doing what you know, and don't be discouraged because loose leash walking is one of the harder things to train a dog - it's like telling a kid to be still when they're in a playground. Butters took 8 months to be "decent", which means most of the time not pulling, but when she's excited, there's no hope. The absolute best method I found for my dog, is rather than corrections, I would do what doxiemommy says, PLUS, treat her every time she is on loose leash, or treat her every time she's in or around your knee around (1 sq foot either direction), so she knows it's rewarding to stay near you. If you are more interesting than the environment, you will know you are, because your dog will be looking up at you, and sort of romping around you, hoping to get your attention. You also want to watch for the signs when she's getting excited (ears pricked, etc), and call her to you before she "explodes" into the pulling, ask her for a sit, and treat her. Do this every time right before you think she's going to pull (And believe me, every dog has triggers - Butters will do it if she sees another dog or person coming our way so I call her over to the grass/curb, ask her for a sit, then treat)
REALLY important: before you set out on your walk (leave the door), ask your dog for a series of behaviours (A sit, stay, down, paw), and just get into that "training" mode. He will know that you are armed and ready to reward him for showing you good behaviours, and will likely be a bit more attentive to you on your walk. ALso practise your recall, so what I do, is at the very beginning of the walk, when Butters sort of leads astray to sniff something, I call out to her, "Come!" and the minute she turns around to return to me, I treat handsomly. After that, she's putty in my hands, and just stares at me the entire walk.
It's not necessary teaching a solid 'heel', it's just getting them to start to enjoy walking next to you (even if it's not a solid heel), rather than pulling. Again, you can ask yourself what you want your dog to do, and what would make your life easier/happier.