In this paper we define two novel design patterns that can be used with statecharts-based agent modeling in many real-world domains that call for open Multi-agent System architectures. The first pattern is based on the well-known factory design pattern, and the second on the composite pattern. The applicability of our proposed patterns is demonstrated with ASEME, an agent-oriented software engineering methodology that uses statecharts for the inter- and intra-agent control models and the popular, FIPA standards-compliant, JADE agent platform. We showcase the patterns usage through an application for the modern vehicle-to-grid (V2G) and grid-to-vehicle (G2V) energy transfer problem domain.