Go to a quiet place (even the restroom if you’re at work and can step away for a moment) and find a comfortable sitting position.
Close your eyes and do a few deep breaths. Focus on those breaths and on the in breath, pull in loving positive energy. On the out breath, push out negative yucky energy. You can also do colors if that helps. Positive loving color could be a light blue or green or your favorite color. Yucky negative energy is usually a dark mucky grey color.