Now that I'm in my 30s, my skin doesn't improve on its own like it used to. So, I am managing it with a routine that reduces stimulation and consistently replenishes.
First, I cleanse as gently as possible and apply only light, hydrating products in the morning. Instead, in the evening, I use a toner to refine my skin texture and focus on replenishing inner dryness with an ampoule or essence. Especially when my skin is dry, I find that applying a generous amount of cream as a finishing touch makes my makeup apply much better the next day.
Exfoliation is also important, but instead of using harsh peels, I tend to use a gentle product about once or twice a week. If I do it too often, my skin actually becomes more sensitive and breaks out.
Lastly, I think the most important things are UV protection and maintaining hydration. I always apply sunscreen when going out, and even at home, if I feel dry, I keep replenishing moisture with a mist or moisturizer.
I think the key to skincare in your 30s is consistently doing the basics according to your skin condition, rather than using a lot of fancy products.