To ensure that the skin-darkening effects of tanning are neutralised, you need to use a face pack aimed specifically at lightening your skin tone. The safest option is to use a turmeric and sandalwood pack. Both these ingredients are commonly found in many skin creams and are easily available.
Try This Pack: Take equal amounts of turmeric and sandalwood powder and mix them with some rose water. Keep this pack on your face for at least 25 minutes before rinsing it off.