The outcome of protein crystallization attempts is often uncertain due to inherent features of the protein or to the crystallization process that are not fully under control of the experimentalist. The aim of this contribution is to propose user-friendly tools that can increase the success rate of a protein crytallization project. Different bioinformatic approaches to predict the crystallization feasibility (before any crystallization attempts are undertaken) are discussed and a novel approach to assess the nucleation process of a given protein is proposed. Practical examples illustrate these two points.