I like to start by finding out what the student believes they struggle with. If the student has something they want to work on, eg homework assignment, we work on that. As we are working I will add additional information about topics and test other skills to see where the student is and to help enhance those skills. If the student doesn't have a specific assignment to work on I will pick a subject and either make up problems or I have some other resources to pull from. I try to have the student show me how they think a problem should be solved before I show them. This helps see what they know and it helps build their skills.