Loose-leash walking is one of the most requested and most misunderstood training goals. The good news is the core method is genuinely simple, even if it takes patience.
The moment the leash goes tight, stop walking completely. Wait for slack to return — your dog looking back at you, sitting, or simply pausing — then continue. It feels painfully slow at first, sometimes turning a ten-minute walk into thirty, but dogs learn quickly that pulling gets them nowhere while a loose leash keeps the walk moving.
Consistency across every walk, from every family member, is what makes this method work. One person allowing pulling undoes a lot of the progress.