The pixie beauty of 25-year-old Park So Dam, star of the K-drama “Cinderella and the Four Knights.”

Not all skin care regimens are created equal, at least not when you’re 40 (as compared to 20). Here, in this three-part series, we start with a step-by-step guide for those lucky enough to be in their 20s.

You may not see any signs of aging, but they’re lurking beneath the surface, so prevention is key.“This is a decade where if we protect our skin from the sun and maintain good skin practices, much of aging can be delayed and prevented,” says board-certified dermatologist Kally Papantoniou. Start with broad-spectrum UV protection in an SPF 30 or higher every single day, and be sure to remove makeup, even after a late night out. Also, adult acne may hit now, so treat without drying out your skin.

Your regimen:

Remove makeup and cleanse every day
Vitamins and antioxidants to brighten and repair
Treat blemishes with salicylic acid
Moisturizer with broad-spectrum SPF 30

TRY THESE:

The cult classic French micellar water removes makeup and hydrates — and it’s finally available in the U.S. Bioderma Sensibio H20, $11.90, beautylish.com

Prevent clogged pores with regular, gentle exfoliation. Laneige Multiberry Yogurt Peeling Gel, us.aritaum.com

Get your vitamin C in this serum with ascorbic acid. La Roche-Posay Active C10, $53, laroche-posay.us

An antioxidant-rich night cream, especially made for the 20-something lifestyle of late nights and lack of sleep. Clarins Multi-Active Night, $56, clarinsusa.com

It doesn’t get easier than a tinted moisturizer with SPF. Pur-lisse BB Tinted Moist Cream SPF 30, $32, purlisse.com