OARS
Reflective listening is key. The best motivational advice we can give you is to listen carefully to your clients. They will tell you what has worked and what hasn't. What moved them forward and shifted them backward. Whenever you are in doubt about what to do, listen. But remember this is a directive approach. Unlike Rogerian therapists, you will actively guide the client towards certain materials. You will focus on their change talk and provide less attention to non-change talk. For example, "You are not quite sure you are ready to make a change, but you are quite aware that your drug use has caused concerns in your relationships, effected your work and that your doctor is worried about your health."
You will also want to vary your level of reflection. Keeping reflections at the surface level may lead to that feeling that the interaction is moving in circles. Reflections of affect, especially those that are unstated but likely, can be powerful motivators. For example, "Your children aren't living with you anymore; that seems painful for you." If you are right, the emotional intensity of the session deepens. If you are wrong or the client is unready to deal with this material, the client corrects you and the conversation moves forward.
The goal in MI is to create forward momentum and to then harness that momentum to create change. Reflective listening keeps that momentum moving forward. A ratio of three reflections for every question asked is recommended. Questions tend to cause a shift in momentum and can stop it entirely. Although there are times you will want to create a shift or stop momentum, most times you will want to keep it flowing.