10 Top-Selling Travel Items and Sets You Can Get at Sephora — Under $28

What it is: Sephora Collection Sleeping Mask ($4)

Why you need it: If you've never tried Sephora Collection skincare products, start with these sleeping masks. They are exactly what they sound like in that you apply a fine layer before bed and rinse off the excess in the morning. There are eight kinds of masks, so odds are there's one for any complexion concern you might have.