Does anyone have a treatment for getting rid of dark circles and undereye puffiness that's worse on some days?

Try an ice pack like. Frozen peas(wrapped in a slightly wet towel ). Then i would guess you have a stuffy nose as well...Since the dark circles are due to the congestion pressing on the blood vessels under the eyes. Then try zyrtecd or allegrad( read labels for precautions etc) and see an allergist if you still suffer.