To calm monkey mind, or to relax before bed spend a minutes doing alternate nostril breathing.  This practice calms your nervous system, quiets and steadies your mind.

Place your right thumb over your right nostril to close the airway.  Inhale through the left nostril.  Use your ring finger to close off your left nostril. Left your thumb and exhale through the right nostril.  Breathe in through the right nostril.  Then put your thumb over your right nostril again and exhale through the left nostril.  Continue in this matter for 5 to 10 rounds.

This will help your body to transition into relaxation for sleep or meditation.  You can also use this practice any time you need to calm monkey mind.