Software shaping workshops (SSWs) described in this paper are software environments designed to support various activities of end-user development (EUD) and tailoring. A design methodology to create easy-to-develop-and-tailor visual interactive systems that are organised as SSWs is illustrated. Users of an interactive system are in many cases experts in some domain different from computer science, who need to perform some task with the aid of the computer system. The design methodology allows users to directly collaborate to the system design and tailoring process to face co-evolution of user's and systems. The strategy feasibility is discussed, outlining its implementation through a Web-based prototype.