In this presentation, I will focus on the functionalization and nanostructuring of graphite, graphene, and other 2D materials using two approaches. A first approach is based on molecular self-assembly at the interface between a liquid or air, and the 2D material. I will discuss concepts of nanostructuring emphasizing the effect of solvent, solute concentration and temperature, and self-assembly under nanoconfinement conditions. A second approach is based on grafting molecules on 2D materials via covalent chemistry. In addition to a discussion on the functionalization principles, it will be demonstrated how also nanolithography can be used to nanostructure such covalently modified 2D materials. Advanced interface specific methods such as scanning tunnelling microscopy (STM) and atomic force microscopy (AFM) provide structural and other types of information at the nanoscopic level.