Research in experimental archaeology, ethnoarchaeology, geoarchaeology, and vertebrate taphonomy has appreciably increased our general understanding of the formation processes—cultural and natural—of archaeological sites. In synthesizing some of these recent advances, this paper focuses on the traces of artifacts and characteristics of deposits that can be used to identify the formation processes of specific deposits. These observational phenomena are grouped into three basic categories that structure the presentation: (1) simple properties of artifacts, (2) complex properties of artifacts, and (3) other properties of deposits. Also considered is the way in which prior knowledge can help the archaeologist to cope with the large number of processes and the nearly infinite combination of them that may have contributed to the specific deposits of interest. Several analytical strategies are proposed: (1) hypothesis testing, (2) multivariate analysis, and (3) use of published data to evaluate formation processes. This paper demonstrates that the identification of formation processes, which must precede behavioral inference and be accomplished by any research endeavor that uses evidence from the archaeological record, can become practical and routine.