High end retouching takes time. And patience. But provided you have the previously mentioned all you need is two techniques basically. Frequency separation and dodge&burn.
There is no point in doing a tutorial since i have learned it on YT myself so i do not think i can make them better, so please feel free look it up on YT.
Could you also share your workflow on retouching process that you do on your images?
Click to enlarge
Shot with Nikon D3s 50mm 1.4G f/8 1/200 iso 200
Have fun,
David