One of the most difficult jobs for requirements engineers is to select an appropriate RE method for the project at hand. Good engineers make good choices and have skills in applying selected techniques appropriately. Poor engineers usually have a narrow choice range limited by their training and biased by their experience. Once a RE technique that does not fit the current project is selected, the project is doomed to fail. In this article, we propose a framework to characterize typical RE techniques and use it as a base for selecting appropriate techniques at the time a project is started, as well as at the time a change in the nature of the project is recognized, or an obstacle is encountered in defining a suitable set of requirements. 