A facial set is already designed as a coherent whole, with products formulated to complement each other and cover several steps of the routine with a single purpose, whether that's hydrating, brightening or caring for signs of ageing. This means you don't have to research what pairs well with what, and these sets often include formats that make it easy to try a complete routine before deciding which product to repurchase in full size.
The usual order follows the logic of any facial care routine: first the cleanser, then the toner, followed by the serum or specific treatment, and finally the moisturiser that seals everything in. If the set includes a targeted treatment, such as an eye cream, apply it before the moisturiser. Following this order helps each product perform its function properly.
There are sets designed for different skin types and goals, so it's best to choose the one that best matches your specific needs, whether that's hydration, oil control, or care against signs of ageing. Checking the composition of each step in the set helps confirm that all the products address the same need before adding it to your routine.
Yes, although you should check that the active ingredients don't overlap or become incompatible with each other, for example avoiding combining several potent exfoliants on the same day. The simplest approach is to replace a specific step in your usual routine with the equivalent product from the set, or gradually introduce the full set while finishing off the individual product you were already using.
It depends on the amount of each product and how often you use it, but these formats are usually designed to last several weeks of a complete routine, enough to assess whether your skin responds well to the combination of active ingredients before deciding which product to repurchase in full size. That's why they're practical both for travelling and for trying out a new routine without committing from the start.