If your dog or puppy has learned the command "sit", don't be fooled into repeating yourself when you give the verbal or visual "sit" command. "Sit" really does mean sit. I am talking bottom on the ground and don't pop up kind of sit. Because "sit" doesn't mean pop up after you plopped it on the ground. Teaching the sit command along with a release word will begin the journey to a relaxed, happy, confident pup and human. 

Tips:

1) Remember to always use your release word anytime you give the "sit" command.

2) Once you give the command, don't repeat yourself.

3) You can lure into a sit position by letting your dog smell a treat near its nose.

4) You can make clicking, kissy or whistling noise to get your dog's attention back to you and your face.

5) Be calm and patient. If the "sit" command is not working for you at a location with lots of sights, smells and distractions, move the practice back to a quieter place with fewer interesting sights and smells.