How to get glowing skin?

These days, every morning, when I sit down at my vanity, I sigh. Before, my complexion seemed bright even with just a simple toner, but now, even with layers of foundation, it feels like it's quickly dulling. Especially in brightly lit cafes, my face feels particularly dark, and I keep checking in the mirror. I envy my friends for their ability to maintain a radiant glow. Even when I slather on moisturizer, it only lasts for a short time, and my skin quickly becomes dull. Every night, I wrestle with the question: should I try an expensive ampoule or completely overhaul my skincare routine? They say a good night's sleep is the best medicine, but it's not easy to get a good night's sleep in our busy lives. I've tried adjusting my diet and drinking more water, but it's so hard to see any noticeable changes. How can I achieve healthy, radiant skin? Ultimately, is the key to preventing dryness from within? Or is regular exfoliation the answer? I've been researching cosmetic ingredients, but there's so much information out there that it's really hard to choose. What routine do you use to achieve clear, radiant skin? If you have any secrets, please share them.