Structure is at the heart of many types of functionality, from color formation and optical manipulation of light to the way living cells interact with surfaces. However, obtaining complex nanoscale structures is currently hindered by the requirement to apply complicated and costly fabrication techniques. I believe that understanding how to obtain structural complexity using simple chemical design rules could lead to breakthroughs in various fields in nanotechnology. In order to obtain this understanding, we need to consider the different forces that lead to self-assembly, analyze their operation under different scenarios, and explain the interplay between them. This knowledge will allow us to devise simple self-assembly schemes that will enable harnessing self-assembly to our advantage with minimal reliance on complicated, multistep fabrication methodologies. Simplicity is key. This approach guides the research in my group. We explore the self-assembly and co-assembly of block copolymers, nanoparticles, polyelectrolytes, and supramolecular polymers under different conditions and scenarios. We prefer to use model building blocks over custom-made components and we focus on combining different elements that influence assembly, such as topography and control of film thickness under extreme confinement, because we believe that only complex behavior arising from simple building blocks has the potential to create paradigm shifts in real life applications.