It doesn't matter for how long you have used Adobe Photoshop, there is always more you can learn. In this video, learn some lesser-known functions hidden away in menus for working on the colors of your images.
I have discussed the depth of Photoshop a few times and it never fails to regularly remind me just how deep it is. I started learning Photoshop about 18 years ago and I remember thinking that there was so much to the software that it was borderline unmasterable. Then, as these learning curves tend to go, I started to build up an arsenal of techniques and tools and felt as if I was getting rather good at it. Finally, when you actually are rather good at it, you realize how much you don't know.
All of these years later and I still feel the same way. In fact, I'm arguably worse because I rarely seek out new techniques anymore. I have all the tools I need to complete the work I do to the standard I want, and there are rarely situations in which I look at an image and think that it could be significantly improved by someone better at Photoshop than I am. This is a limiting way to work, particularly with software as fast-changing as Photoshop.
In this video, Photoshop Training Channel walks you through some automated tools that are a little hidden away. A few of these techniques I was aware of, but the first example I had absolutely no idea it existed.