Understanding and control of crystal shapes is highly relevant in the fields of industrial crystallization and geology. The Netherlands has a long tradition in crystal morphology prediction. Hartman and Perdok developed the widely used Periodic Bond Chain theory in the 1950's. This theory has been refined in subsequent years by our previous group leader, Prof. Bennema. We combine this geometrical theory with statistical thermodynamics models for crystal growth to understand the morphology of a wide range of crystals. By looking for stable step orientations on crystal faces and predicting the relative growth rates of the faces, morphology can be predicted. For determining step energies we have developed a numerical routine STEPLIFT. Numerical simulation of growing crystal surfaces can be performed using the Monte Carlo program MONTY. The outcome is compared with actual crystal growth experiments.