Puppies are generally high energy and in need of some training, and one of the most important training tools you will buy is the puppy leash. Choosing the best one starts with determining the size of your puppy as well as how large your puppy is likely to be as a full-grown dog. It is likely that you will need to buy a puppy leash that is suitable for your new dog when he or she is young, and then replace that leash with a larger one once the puppy grows to full size.
A small, nylon show leash is a good choice for a puppy leash because these tend to be inexpensive, lightweight, and small. You can begin to train your puppy with this type of leash without having to invest in a larger, heavier leash that may be too cumbersome for a small puppy, and when it comes time to replace the puppy leash with a full-size one, you will not have bought an expensive leash just for the dog's puppy stages. Try to avoid leashes that have decorations that can come loose; dogs tend to chew on leads when they are young, and decorations can come off and choke the dog.
You will have to choose between nylon leashes and leather ones. A nylon puppy leash will be durable and will be resistant to water damage, but it can be harsh on the hands over time. Leather leashes tend to be comfortable for you, not to mention quite attractive, but they can be damaged when exposed to moisture and your dog is likely to want to chew on the leather. If you are looking to save some money, you may want to stick with nylon as well, since leather can be more expensive.
If you need to gain control of your dog from a long distance, think about a retractable puppy leash. These units feature a plastic handle, as well as a long cable or rope that can retract or lock when you need it to. This allows your dog to roam farther from you, but if you need to get control of the dog in a hurry, you can lock or retract the leash to bring the dog back to you immediately. These are not the best choice for obedience training, however; you will probably want a shorter, lighter, and less cumbersome leash if you intend to perform training exercises with the puppy.