My dog has a hard time concentrating during training sessions, even when I use her favorite food. What should I do?

Keep her training treats in a bag around your waist. In the house, whenever you remember you have a dog, do a quick training session, such as asking her to sit and then to lie down. Reward her. Training little and often teaches her to pay attention to you. Train in an environment where there are few distractions, such as at home or in the yard. As she learns to focus, take the training out on walks. Also, teach her the "Look" command as a way of holding her attention on walks when she may be distracted by people, dogs, or bicycles.