I tend to use it after correcting highlights, shadows, vibrancy, clarity and perhaps contrast. In the latest versions of LR you can simply double-click on the word Whites and Blacks whilst holding down the shift key. That will automatically set the ends of the histogram. It works satisfactorily most of the time but occasionally I need to back off a little.
See this tutorial:
Lars RS wrote:
Hi. Does anyone set black & white points while editing? If so at what point in the workflow do you do this?
There are no rules (and people who tell you there are need to examine the art of rendering a photo). Case in point, this well know photographers disregard for shadow detail and for good reasons:
What is recommended is working top down with the controls, so Exposure first, than move down from there. You can always change your mind, it's how you the image creator wish to express the image that counts.