How do you sit and breathe for mental imagery?

Here's a short video for how to sit and breathe before and during mental imagery exercises.

Key points:

• Sit up in a chair. Keep your back straight and rest your arms comfortably either on armrests or your lap. Place your feet flat on the floor, and don't cross your hands or your feet.
• Close your eyes. 
• Breathe out a long, slow exhalation through the mouth, and follow it with a regular inhalation through the nose (i.e. don't exaggerate the in-breath). Repeat this breathing sequence for a total of 3 times (often you'll see in my book "breathe out 3 times" or "BO3X").  
• Do the imagery, breathing in your normal pattern/rhythm. 
• Breathe out once and open your eyes.