Cryo-EM is a revolutionary tool that reveals high-resolution structures of macromolecules. In this talk, I will introduce our recent work on assessing the quality of experimental data using CryoSieve. We have discovered that more than half of the particles are not useful to the final reconstruction. In some cases, the remaining particle count is nearing theoretical limits. Furthermore, I will introduce CryoPROS, a new tool for particle generation, which offers significant capabilities for addressing the preferred orientation issue.