My personal skincare secret that I use regularly, is it really effective?

My vanity is full of products, but only a few I reach for frequently. This leads me to develop my own personal skincare essentials. Finding those skincare essentials that are gentle on the skin and yet make a noticeable difference in its condition can be more challenging than it seems. Especially when the seasons change or my skin becomes more sensitive, having just one essential skincare essential can make skincare much easier. Based on my own experience, not advertising, I'd like to know how you choose your personal skincare essentials. Also, if you have any practical tips that even a skincare beginner can easily follow, I'd love to hear them.