QCA (Quantum-Dot Cellular Automata) is an emerging nanotechnology that has the potential to replace current CMOS technologies. QCA permits extremely low power consumption, since its working principle is not based on electric current flow but on Coulomb interaction. The development of Electronic Design Automation (EDA) tools and flows is an essential step towards the applicability of QCA for integrated designs. However, the scarce number of works in this field highlights that there is plenty of room for the development of new EDA methodologies for emerging nanotechnologies. Standard cells play an important role in this context, since the development of routing and placement algorithms are strongly related to their existence. This work presents a methodology for standard cell design for QCA as well as the exemplary QCA cell library ONE, which is based on the recently proposed USE (Universal, Scalar and Efficient) clocking scheme. Two representative case studies indicate the feasibility of the approach.