Distractions - start 'cool' and work up to warmer and hotter variations. Keep in mind, every dog is different! What may be “cool” for one dog is “warm” or “hot” for another.
Challenge your dog’s Prey Drive & Natural Curiosity - things like food, toys, etc. that represent 'prey' to your dog, and incite a chase response.
Challenge your dog’s Social Drive - people and other dogs - things that influence your dog’s feelings of security and social well-being.
Challenge your dog’s Defense Drive - things that spark 'fight or flight' responses in your dog.