The reasons that motivate a person vary from individual. So the first step is to talk with a student enough so that I can understand what does or may motivate them. For some, reaching specific goals can be quite motivating. For others, it may be more about feeling that they have mastered the material. For others, it may be rewards. Whatever the motivation, I think it's important to encourage a student's progress. Nothing can be as demoralizing as feeling like you are not moving forward. At key moments, it can also be helpful to remind students of what they are working towards. How would you help a student get excited/engaged with a subject that they are struggling in? It can help to look at the subject from a different perspective and to show the student that the subject is applicable to his/her interests. (Like connecting math to a sport the student plays...) Finding a new format to work on the material can also be helpful. A more interactive format can be especially effective. (Examples: playing a game instead of doing standard math problems, doing an experiment together to illustrate scientific principles...) How do you build a student's confidence in a subject?