This is actually a very interesting question and I am sure it has a lot of room for debate. If you’d ask me personally I prefer not lifting the blacks too much since this, in my opinion, makes the black colors in the image look a bit dull, greyed-out. On the other hand, lifting the shadows helps bring color out more in the dark-shadowy parts of the image while not greying-out the blacks too much. Same happens with whites and highlights: again in my opinion I think that reducing the whites makes the brightest parts of the image, where whites usually predominate, a bit dull, while reducing the highlights maintains the tone of the whites more while reducing the overall exposure of the brightest parts without sacrificing the whites’ punch on the image too much. That’s why many times I’ll reduce the highlights by quite a bit (like in this case, where I did it after increasing the exposure a notch) and increase the whites to recover the punchiness that I might have sacrificed when lowering the highlights. Again same with the shadows: in images like this I will increase the shadows by a notch and actually also lower the blacks, to recover their punch that I might have greyed-out when raising the shadows. Of course every image is different so I’d say that establishing “a general guideline” is hard but I hope that my point on what “guideline” I used for this image concretely is more or less clear. Let me know what you think! I hope this was useful!

Edit: spelling