It is commonly believed that the success of a company lies in the management of its knowledge, which is strategic resource for innovation and continuity. However, the most valuable knowledge is also tacit. It is difficult to be preserved, to be made reusable and to be enhanced, because it lies in people's minds and it is hard to express and share. Knowledge engineering techniques have been adapted and used for knowledge management, especially, for the acquisition and modelling of this kind of knowledge. In this paper, we present MNEMO (Methodology for kNowledgE acquisition and MOdelling), a mixed methodological approach, which combines the strengths of two of the mentioned techniques, CommonKADS and MASK (Method of Analysis and Structuring Knowledge), both analyzed and evaluated through real applications in specific domains. The goal is to dispose of a global method, which aims to be more complete and flexible for knowledge management purposes, with particular attention to modelling activity.