Molecule and particle base simulation methods provide useful tools to gain mechanistic insight into the nucleation of crystals from solutions. With proper sampling, quantitative thermodynamics and kinetics can be obtained to compare with experiments and test theories for crystal nucleation. In this review, we have highlighted state-of-the-art techniques to gain such information. These can be broadly categorised as methods which rely on theory with a well-defined reaction coordinate-mainly CNT-and those which are truly explorative.