What is the one thing that actually moved the needle for you after 45?

I want to hear real experiences, not marketing. For those of you past 45 who feel genuinely good about your skin, what was the change that made the biggest difference? Was it finally committing to daily sunscreen, was it a prescription retinoid, was it giving up the harsh stuff, was it something about sleep or hydration that had nothing to do with products? I ask because I have a tendency to chase the new serum, and I suspect the boring answers are the real ones. I am 49, mostly worried about loss of firmness and some uneven tone. Not looking to look 25, just to look like a rested version of my own age. Tell me what you would tell your younger self about your forties skin.