There is one best way to manage projects. There is one best way to plan. There is one best way to develop new products. There is one best way to engineer software. There is one best way to drink beer. There is one best way to clean the shower. There is one best way to get kids to behave. There is one best way to pray.
Well, on second thought, maybe not. Though you don't hear that much from people. More common is the evangelical acceptance and propagation of "a way" as being the best or only way. People like to be in the group that "knows how to" do something. People enjoy the assurance that they are "right". It is comfortable to be in the middle of a herd of wildebeast when there is a lion on the left and a leopard on the right. Of course some don't also, but that is OK too. Lions have to eat.
These thoughts pop out of my head after reading a couple different things. The first, David Anderson's plea to the Agile community to broaden the description of what "Agile" is to the point where it is almost everything (presumably with the goal of gathering more and more wildebeast into the fold - can you make cheese from wildebeast milk?) - a sort of ideological gerrymandering I think, in which rather than a process, "Agile" is defined as the result. The second a discussion on the New Grange mailing list about the nature of expertise.
Of course, like all thought, the bread rises before it is baked, so I have no special treats from the oven for you yet, but perhaps you can take the half-baked dough and cook it in your own oven. Think about what sort of soil conditions you have around you and what sorts of plants will flourish in it, and which will die. Think site-specific. That is one way to go about it.