In nature, complex microstructures and material architectures are achieved by self-assembly and relatively slow growth. For technical applications, which require fast and high volume production, the challenge persists to develop manufacturing processes with which it is possible to synthesize materials that mimic both structure and performance of their biological counterparts. One process with which it is possible to manufacture such hybrid materials is freeze-casting. It utilizes two intricate processes, directional solidification and self-assembly, to create structures that can be controlled across several length-scales. As a result, freeze-casting permits to create highly porous materials with mechanical properties that are an order of magnitude better than those with the same overall porosity and cell walls of identical composition but a more random structure. Illustrated will be, how depending on the choice and combination of components freeze-casting permits to create complex materials with a diverse spectrum of properties that can be custom-designed.