Help them with their homework. Even if they can do it on their own, check it over with them to make sure it is correct, be available to answer questions or to listen to them read their essay, and ask how they completed a certain math problem. It shows them that you are a resource they can go to if needed. You also will keep up to date with what they are learning so you can ask the teacher for guidance. If their work suddenly takes a drastic nosedive, it may be an indicator that something is wrong — either academically or socially.