Just as militaries have their doctrines, so too the humanitarian aid community has its principles and best practices. Like military doctrine, it can be imperfect, poorly understood, unevenly accepted, and badly interpreted and implemented, but they do provide some indication of how things should be done--including the issues that Curmudgeon raises (need, coherence, coordination, stakeholder consultation, host country ownership, not imposing external values).

Some links and light reading,for those so inclined:

Principles and Good Practice of Humanitarian Donorship (the "Stockholm Declaration," 2003).

Paris Declaration on Aid Effectiveness (2005).

OECD, Guidelines on Helping Prevent Violent Conflict, Principles for Good International Engagement in Fragile States, among many others.

On top of this, almost every specialized international agency has a "lessons learned" or "best practices" department, and many of their publications and reports can be found online.

What we tend to be missing is a systematic examination of "worst practices" and why they occur and reoccur. I've always thought that understanding the pathology of repeated errors is critical to correcting them.