It has been known for thousands of years that our bodies radiate energy, that we have a magnetic field, more recently measured and proven by science (sometimes called the peripersonal space). The energy we radiate out is actually part of our immune system and also an extension of the intelligence of our bodies. Below is a practice that helps to strengthen and bring awareness to this outer, protective layer of our energy field.
Begin by placing your feet on the floor/earth. Feel your connection to the Earth by slowly and gentle shifting your weight from one foot to the other. Notice the sensations in your feet and how they connect to the ground. Notice what you see around you and how it feels to be standing.
Next, place your hands on your tan dien (Sea of Chi), below your navel on your lower abdomen. See you if you can feel your breath here, gently moving your belly and hands in and out on your inhale and exhale.
Now, imagine/feel your breath expand from here and your chi/energy begins to expand inside of your body and then radiates outside of you to form a protective energy bubble. Trace this bubble with your hands, moving your arms and hands all around you. Behind you, to the sides, underneath you, above you and in front of you. Notice what happens in your body and nervous system as you make these boundary movements.
If you want to go further, imagine/see/feel colors coming out of your hands and splash or spray paint the inside of your energy bubble with whatever colors feel good - fortifying and strengthening your chi bubble. Then, place silver mirrors on the outside of your bubble, which will reflect anything that is not helpful. Your chi bubble is like a protective membrane, allowing what is welcome to come in and keeping out unwelcome energy, projections, toxins etc.
Take some time to stand here and feel yourself grounded and protected inside your personal energy bubble.