When you're working on creating a personal routine, it's easy to be mystified by names and purposes of different products. As you sort out each step, the line between them often gets hazier and less black and white. Similarly to ampoules and serums, things like exfoliants and peels or toners and essences are often interrelated or overlap in their uses, but knowing the characteristics of your products can make a huge difference in how your skin benefits.
Because ampoules are viewed as more of a special treatment, you'll want to incorporate them after cleansing and applying toner and/or essence, but only for a couple of weeks at a time (via The Glow Edit). Serums on the other hand can be part of your routine morning and night and should go on after the wash and tone section of your routine. But, it's worth noting that the two can be used together — your serum should just come after your ampoule.
