How do you tell if a cv driveshaft is bad?

First signs of a bad cv is, clicking noise when making a sharp turn. Alot of times the cv boot ( rubber boot that covers the cv joint and holds the grease in ) tears and leaks the grease out, you can turn the wheel all the way and take a look at the boot where the axle attaches to the wheel if there is a rip you will see grease everywhere, if the cv isn't clicking yet it will soon.