Getting blackout curtains may be tempting if you're feeling lackluster, but Dr. Yeager advises doing the exact opposite. "Flood your home or office with as much light as possible. When curtains are drawn or blinds are closed, you don't benefit from any natural light that's out there. If necessary, rearrange your interior to maximize any sunlight that filters through on cloudy days."
If your home/office doesn't have great natural light, he suggests purchasing a light box to mimic outdoor light.