Giant magnetostriction materials, such as Terfenol-D, have allowed the development of a new class of actuators and sensors based on magnetoelastic properties. However, their mechanical properties are a limiting factor for some applications. Composites, made of Terfenol-D particles in a matrix, can bypass these limitations, improving the overall mechanical properties while maintaining the magnetostriction effect. But, to optimize the design of magnetostrictive composites, advanced modeling tools are needed. This paper proposes a homogenization model based on inclusion problems. It compares modeling results to experimental data from the literature, and it illustrates the use of the model as a tool for optimal design.