I have some photos with green color casts from grass in the foreground/background. I used the WB eyedropper to select either what should be white or grey in the image.
1. To get the white balance as accurate as possible, is this why I should use a white balance card for one of the photos in my series so I can use the LR WB eyedropper to sample the white balance card?
2. When do you want to sample either white or grey in an image? Is there a reason to go with one vs. the other or is it just a matter of personal taste?
3. Should the WB be set before making any other changes in the Develop module?
1. That is right the White Balance eye dropper tool is used to select the neutral of the image.
2. It entirely depends from person to person that uses the White Balance tool.
3. That depends on the workflow that you want to opt for in developing the images.
Please refer the following article:
Please let us know if it helps.