Below is a mindfulness exercise that I often practice with clients. It scans the body, focusing on acceptance of whatever is present, and uses the breath to release any stress or tension. It is based on an exercise from an amazing workbook that I highly recommend, Finding Life Beyond Trauma. Its citation is below.
Follette, V.M., & Pistorello, J. (2007). Finding life beyond trauma: Using acceptance and commitment therapy to heal from post-traumatic stress and trauma-related problems. Oakland, CA: New Harbinger