Decorative ornamentation involves a careful balance between accent and order. Existing techniques leave artists either with tedious manual processes or the uncontrolled automatic generation of rather homogeneous patterns that lack creatively-placed visual highlights. We present a method to close this gap, offering the control and quality of manual creation, and the efficiency and accuracy of computation. At the core of our system, customizable and modularly combinable element placement functions fill a space automatically under global design constraints. We provide a set of example placement functions that implement order based on design principles for ornamentation such as balanced element distribution and symmetry. To create structural hierarchies and to guide an ornament to the space it fills, we allow artists to direct the connectivity of elements with drawn strokes. Artists can also draw guides to create vector fields, which organize the ornament along streamlines. Path planning automatically routes around obstacles while aligning the ornament to their borders. Our method combines high-level control mechanisms like taking guidance from example images to low-level control like placing single elements as visual accents and making local edits within the computed ornament. By automating tedious tasks and offering familiar input mechanisms like drawing, we enable artists to focus on the creative intent