Make sure that you drink at least 8 glasses of water a day. It will help your body stay hydrated and flush it free of toxins as well. At the same time, it will make your face glow and shine.
Always wear a sunscreen lotion when you go out in the day, to protect your skin from harmful ultra violet (UV) rays. Make sure that you are using a sunscreen with at least 15 SPF.

Your tip about the sun screen is quite right. To see the difference between skin that is habitually exposed to the sun and skin that is not have a look at an area of your body not normally exposed to the light and then compare the skin there with the skin of your face! Big difference! One good area to try is the are under your arms, under the wrist area and then up to your elbow. This area will be markedly different and so will the skin of your butt, if you are not a nudist!