People we work often report positive benefits of three mindfulness exercises that supports them to better regulate their negative emotions:

Body scan
Scan your body from top to bottom and notice areas of tension and discomfort.  Do it without judgements, if any judgements arise, gently dismiss them…Make sure that you take a deep breath into each area of discomfort. The purpose of it is not to change anything about how you feel but to become aware of any sensations.  If any change occurs, notice it and also notice also any areas of your body that feel comfortable and relaxed, breathe into these areas and fully experience these sensations.

Connect with a sound
Put on music; listen to the soothing sounds of waves, nature, or tune into any other naturally occurring sounds around you (the hum of electronic appliances, the sound of traffic, birds outside the window). Close your eyes and tune in to any sound you chose. Focus fully on the sound and when you mind wanders acknowledge it and return your attention to the sound again.  

Mindful walking
Go for a walk outside or around your room. Notice what you feel when you are walking, the sensation of your feet when they touch the ground. Also notice how your legs and body feel when you walk.  Focus on these sensations completely.  If any thoughts, emotions or other distractions occur just acknowledge them, without judging and return your focus on the sensations of walking.  Be mindful of every step as this is very important for training your focus.