This practical handbook on Diffusion Weighted MRI techniques provides a concise and schematic overview of several key aspects of this imaging modality. It covers the workflow from image acquisition to data processing, and provides context and examples of its application for imaging the brain and other body districts. The practical aspects of diffusion MRI, key mathematical principles and derived metrics underlying diffusion tensor imaging (DTI) are explored in depth, illustrating some advanced methods to overcome the limitations of DTI itself. This manual also names some of the main software tools available at the time of writing for processing, and provides step-by-step explanations of the main processing steps with examples to enhance understanding of the post-processing data workflow. This manual is intended for imaging professionals, including MR technologists and radiologists in training, as well as other professionals who routinely use MRI.