In archaeology, the robustness and accuracy of field data, which are unique due to the destructive nature of excavation, condition subsequent studies of past lifestyles. Few articles, however, describe, justify and discuss the excavation methods adopted. This often causes difficulties for researchers wishing to resume the study of a collection, compare data between different sites and also raises questions about the reproducibility of our field practices.In this article, we describe the excavation methods used at Combe-Grenal and Le Moustier (Dordogne, France), after attempting to justify and explain the nature of the data required by the various specialists (by drawing up specifications). These two sites, which are very rich in archaeological artefacts, required us to consider how to optimise the methods of acquiring field data in terms of time and consumption of plastic bags. Two simple technical solutions proved particularly effective: a) the use of a single, continuous numbering system for all the data and b) a system of compartmentalised trays and boxes. Throughout the article, the dialectic between needs, data, methods and justification for the choices made is discussed.