For me it's keeping it hydrated as that helps reducing wrinkles, improves the appearance of my skin and prevents rashes.
I ALWAYS make sure to wash my face morning and night. My evening routine consists of a gentle cleanser, exfoliating toner, Hyaluronic Acid serum, and a good quality Retin A moisturizer. I use a face mask 1-2 x per week either a alpha hydroxy peel or purifying mud. The most important part is consistency. You have to be diligent to see results. And don’t forget the sunscreen!
Moisturizing. Super important to wash my face at night, but I’ve found that washing it in the morning as well dries me out, and only washing once is actually sufficient. I dab the oil off my face in the morning and moisturizer my problem spots, then wash and moisturizer before bed. As long as I keep up with it my face is actually okay
I would say the most important parts are hydrating and applying sunscreen. These are the basics we need to do to our skin for it will help avoid the major skin issues we face.