Enzymes are increasingly being used in an industrial setting as a cheap and environmentally-friendly alternative to chemical catalysts. In order to produce the ideal biocatalyst, natural enzymes often require optimization to increase their catalytic efficiencies and specificities under a particular range of reaction conditions. A number of enzyme engineering strategies are currently employed to modify biocatalysts, improving their suitability for large-scale industrial applications. These include various directed evolution techniques, semi-rational design techniques, and more recently, the de novo design of novel enzymes. Advances in mutant library design, high-throughput selection processes, and the introduction of powerful computer algorithms have all contributed to the current exponential growth of the field of enzyme engineering. This review article aims to present some of the currently employed strategies for enzyme engineering and attempts to highlight the most recent advances in methodology.