Moisturizer
Moisturiser is what holds a routine together. It seals in the steps before it and keeps the skin barrier intact, which is what stops irritation, flaking and the rebound oiliness that comes from dehydrated skin.
Moisturizer for dry skin
If skin feels tight after cleansing or looks flaky by midday, you need richer hydration and you need it applied to slightly damp skin, which traps considerably more moisture.
Moisturizer for oily skin
Oily skin still needs moisturiser. Skipping it is what triggers the skin to overproduce oil in the first place. Choose a lightweight, non-comedogenic formula that hydrates without heaviness.
Where it fits in your routine
Cleanse, then tone, then moisturise. In the morning, sunscreen goes on last, after moisturiser has absorbed.
Using it with exfoliants
If you use a glycolic acid toner, moisturiser is not optional. It buffers the exfoliation and keeps the barrier comfortable while your skin adjusts.