Thousands of languages are currently in danger of extinction without having been adequately documented by linguists. This fact represents a tragedy for communities in which endangered languages are spoken, for linguistics as a discipline and for all of humanity. One major role of the field of linguistics is to describe languages accurately and thoroughly for the benefit of all concerned. This paper presents the results of an informal survey of major users of grammatical descriptions and gives lists of dos and don’ts for those contemplating a descriptive study of one of the many endangered languages of the world. Concrete suggestions are provided that will help grammar writers produce user-friendly, thorough and useful grammatical descriptions.