Try this Mindfulness Meditation

Find a posture on the chair or cushion in which you can easily sit erect without being rigid.   Let your body be firmly planted, your hands resting easily, your heart soft, your eyes closed gently.  Become aware of your body and consciously soften any tension.     

Bring your attention to the sensations of your breathing.

Take a few deep breaths to sense where you can feel the breath most easily, as coolness or tingling in the nostrils, as movement of the chest or rise and fall of the belly. Let your breath be natural.   

Feel the sensations of your breathing. Your mind will probably wander. When you notice this, no matter how long or short a time you have been away, simply come back to the next breath. Before you return to  your breathing, you can mindfully acknowledge where you have gone with a soft word in the back of your mind such as thinking, wandering or worrying, Gently return to feel the next breath. Calm yourself by relaxing into your breath. Your mind will want to run all over the place but...like training a puppy, gently bring yourself back a thousand times, not with harshness as you want the puppy to remain your friend. With loving kindness bring yourself back to your meditation of your breath.

Check out apps- Sattva, Headspace: Meditation techniques or Calm.com