In my experience, the chief thing I ask is what materials are used, it is such a basic question, but it has really made all the difference in my own issues.
2nd would be asking like how many different shades there are in specific spots, so you can compare them to how you would paint them, if you had painted them the way you did before.
3. is also a more practical one, I would ask what tools you used, what size brushes etc.