Speak clearly and loudly enough to be heard. Make your first point that you are interested in the position for which you are applying. Synchronize yourself to the interviewer. Watch for their reactions. Adjust to their speed and mannerisms.
People feel more comfortable when they are in sync.
Tactfully lead the interviewer into asking about your good points, your skills, your training, or your enthusiasm. Briefly answer questions with out being abrupt. Take your time. Let your questions show your interest in the job. Be sincere and honest.