HYDRATE YOURSELF : Drink plenty of water both preflight as well as during the flight to compensate for the water loss from the skin due to low humidity.

MOISTURIZER: Apply moisturizer both pre-flight and during flight. I suggest using a thick cream based moisturizer with sun protection . You will notice how fast the moisturizer gets adsorbed on your skin in the flight. If you are for a long haul, reapply moisturizer every 2 hours. This is the earliest way to keep skin from drying out.

LIP BALM: Don't ever forget to carry your lip balm. This not only helps to keep your lips moist but also nourishes it.

FACIAL OIL: You may even use a facial oil as an alternative to moisturizer only if you have dry skin.

SHEET MASKS: These are the last resort until and unless you are looking for some unwanted attention. If you do, use oil based sheet masks as they don't get dried up easily and helps maintain the face hydrated and supple.

HYDRATING MIST SPRAY: Avoid using hydrating mist spray during flight. Since water attracts water, when you spray your face, it takes water from the layers in the skin and it all gets evaporated into the dry air. (Remember that osmosis I told you about).