I wish it was as simple as telling you to set them to max or min, but it is not that easy. The reason for the adjustably is to work the trip characteristics around the upstream and downstream device's characteristics.
There is no easy answer, and generally requires and engineer to perform a study. I will try to find some web links that you can review, but it takes years to be able to get a handle on the art of protective device settings. Many times you have to decide on one extreme regarding reliability and on the other side of equipment protection and reduction of arc flash incident energy. It is not an easy topic because there are many things to consider.