In recent years, structural DNA nanotechnology has fulfilled its promise of generating complex, self-assembled discrete and periodic nanostructures (1,2). One of the original goals of this technology was to use self-assembled DNA nanostructures as designer scaffolds for directed molecular assembly. Achieving a higher level of control over the fine, nanoscale features of DNA nanostructures is essential to this purpose. In this talk I will present our recent efforts in exploring new design principles for assembling more complex DNA nanostructures including curved DNA origami (3) and topological nanostructures (4), as well as our latest progress in DNA gridiron design.