One of the most common alternatives to a collar is a harness. Veterinarians routinely recommend that dogs, such as pugs with their short noses, and miniature poodles with their propensity for collapsing trachea wear harnesses. However, it's important to chose the right one. In general I avoid harnesses that hook on the back unless you want to train your dog to pull a cart or a sled. These harnesses actually help train your dog to ignore you and pull you because when you pull on the leash to try to gain some control, they direct the dog's attention away from you.
Once the dog loves putting his nose into the head halter and the owner puts it on, the owner may need to engage the dog in fun behaviors to distract him from the funny object on his face until the dog gets used to it.