To properly use a dog leash, you should first ensure that the leash is the appropriate length for your dog and the environment you will be walking in. A shorter leash is better for more crowded or urban areas, while a longer leash may be more appropriate for more open or rural areas.
When walking your dog, hold the leash with your dominant hand, leaving enough slack in the leash so that your dog has some freedom of movement but not enough that they can wander too far away or get into trouble. Keep your arm relaxed, and avoid jerking or pulling on the leash. Instead, use a gentle but firm pressure to guide your dog.
It is also important to train your dog to walk on a leash, so they learn to follow you and stay by your side. This is usually achieved through positive reinforcement techniques such as treats and praise.
Always keep your dog on a leash when in public places and obey leash laws for your area.