Sit with both feet on the floor. Put down any objects you are holding (pen, book, etc) and place your hands on the table in front of you or in your lap, either palms up or palms down. If it feels right to you, close your eyes. Take 2 deep belly breaths. Imagine the air entering through the soles of your feet and drawing up through the top of your head. Exhale from the top of your head out through the soles of your feet. Then ask yourself these questions:
How does my body feel right now?
What emotions are running high for me right now?
What thoughts occupy my mind right now?
Acknowledge these things; allow yourself to have them.
Gently lay them aside and bring your attention into the present.