The instructor themselves have to be self motivated in order to be effective to be motivational to the students. The difference between commitment and compliance.

Sharing real life experiences and explaining how the real world is in the field show that you care about their development and set up preparations on what to expect or anticipate. 

Being positive and enthusiastic about the subject, or what you're teaching will project to the students and make for a better learning experience.

To make a real life connection with the students. Understand that they are looking for not just an education, but guidance where they can implement what they have learned to their every day lives. Be a part of their personal development.