Understanding the unique properties of sub-10 nm metallic nanoparticles is crucial to developing improved and novel nanomaterials. The accurate and controlled production of metallic nanoparticles below 10 nm is highly desired for model studies in catalysis and materials science. Combining a robust and reproducible nanoparticle preparation method with advanced in-situ/operando characterisation techniques will enable researchers to focus on the science and not the synthesis.