Training consists of Engagement - the ability of your dog to want to play, interact, engage, and offer behaviors to you Teaching - Shaping commands, rewarding for success, withholding reward for no success.
Correction - A correction is "anything that changes behavior".
Make sure your dog understands the exercise fully before you initiate a correction.
Proofing: Introduce Distractions to command well taught.
Reteach the exercise, then proof the exercise in the new situation.
A new area is a new distraction. Just because your dog has an awesome "sit" command at home, does not mean he will "sit" in a different environment.
Don't be afraid to take a step back in training. If your dog is confused, this will lead to mistakes.