This paper presents an analysis, implementation and evaluation of the physical mobile interaction techniques touching, pointing and scanning. Based on this we have formulated guidelines that show in which context which interaction technique is preferred by the user. Our main goal was to identify typical situations and scenarios in which the different techniques might be useful or not. In support of these aims we have developed and evaluated, within a user study, a low-fidelity and a high-fidelity prototype to assess scanning, pointing and touching interaction techniques within different contexts. Other work has shown that mobile devices can act as universal remote controls for interaction with smart objects but, to date, there has been no research which has analyzed when a given mobile interaction technique should be used. In this research we analyze the appropriateness of three interaction techniques as selection techniques in smart environments.