Wear makeup if you have a dark beard, a tendency toward 5 o'clock shadow, a high forehead or a receding hairline. Brush face with cornsilk or translucent pressed powder to help reduce shine and perspiration. Avoid too much lipstick and keep it the same color as your tongue to look natural. Avoid natural color eyeshadow. Keep it light, and avoid the kind that shimmers.
Television is a visual medium.
Rather than sitting behind your desk during the interview, schedule a location that not only is visual but compliments your point of view. Consider and arrange the background. Ask students or others to wear Caltech shirts, if appropriate. Look for props or visual examples. Avoid backgrounds that look shabby, cluttered or outdated.