A good treat bag is essential to keep those high value rewards for good behavior handy. We love this bag by Wildebeest. It has room for the essentials and some extras too. It has two pockets inside so you can keep your keys and poop bags handy, or like us have two kinds of treats. It washes in the clothes washer and is not bulky to wear. The velcro closure is easy for one handed use and the bag can expand to securely hold enough training treats for an all day outing.