Solving structures of large macromolecular assemblies to gain fundamental insights into biological mechanisms remains a major challenge in structural biology. Cryo-EM combined with image processing is currently undergoing what has been referred to as a “resolution revolution”, making it one of the most powerful techniques to address this challenge. It also has unique capabilities to obtain structural information in situ within complex environments, and to deal with heterogeneous samples. The methods are complex and under constant development, so in depth, advanced training of new users is essential to ensure future users can adapt new technologies to expand into new areas and solve new biological problems.