Prof. Jin-Quan Yu and Keary Engle have written an excellent perspective article that draws upon much experience in the Yu lab investigating the balanced relationship between catalyst design and reaction scope.
The article talks about some of the details and origins of priveledged ligands for catalysis and also provides some insights into ligand selection with respect to the substrates and types of reactions you wish to perform. A great and informative read for anyone interested in catalysis, not just those interested in C–H functionalization.