Serving size: An almond

You can be a little more generous with rich night creams than serums because your skin goes into repair mode while you sleep. Stay within the size of almond to avoid an oily, greasy face in the morning.

Serving size: A cherry tomato for masks applied to the entire face, a grape for targeted masks applied to specific areas, like the T-zone

Pore refining masks can zap your skin of moisture if over-applied. When applying to targeted areas, use only a grape-sized amount. For the whole face, use as much as cherry tomato.