This chapter presents a different use of sketch-based modeling, namely the modeling of complex objects from a single sketch, illustrated by the examples of dressing and hairstyling a virtual character. Knowing the nature of the object being modeled eases the extraction of information from a sketch, so that a single sketch depicting a front view (and optionally a second one from the back or side) is sufficient to specify these complex 3D shapes. We show how different levels of prior knowledge about the object being modeled, from basic rules of thumb to more intricate geometric or physically based properties, can be used to interpret the sketch strokes and to infer the missing 3D information, leading to different degrees of visual realism. In addition to discussing practical solutions for the sketch-based modeling of garments and hair that save several orders of magnitude of user time compared to standard 3D modeling methods, this chapter provides the basis of a general methodology towards the design of sketch-based interfaces for complex models.