There are a number of strategies I have used for loose-lead walking. Here are my suggestions.
How old is your dog? If the dog is a little pup and unfamiliar with the leash, lure the dog with a treat to walk forward, following you (as you walk backward).
At this stage, also work on the "watch me" command. Hold a treat up to your face with the verbal command. When the dog makes eye contact, give the treat. Hold the dog's attention for longer and longer as you perfect the command.
Once the dog is comfortable with the leash and knows "watch me", you can work on loose lead training. Hold a treat in your hand, get the dog's attention and take a few steps. If the dog strays, immediately stop and get it's attention. Take a few steps again. If the dog doesnt stray, give the treat. You wont get far at this point, but that's not the goal.
As you start to take more and more steps, if the dog starts to stray, you can quickly change direction. For instance, turn around 90 degrees and go back the direction you came. The more you change direction, the more the dog will have to pay attention to keep up. It is actually pretty fun to zig zag around with the dog watching for your next move.
Eventually, the dog will stick with you and walk on a loose lead. It doesnt have to be a strict heel the entire time, but the dog will stick near you and watch for the dropped treat or the direction change.
Cedar (tri), Willow (blen), & Holly (ruby)