For the past seven years I have been reediting, translating, and studying the magical handbooks from Roman Egypt preserved on papyrus. A magical formulary is a collection of instructions for the performance of different spells and rituals, generally designed for private use. These “recipe” books systematize traditions of knowledge developed to deal with a wide range of everyday human concerns. Such instructions for ritual procedures (praxeis) are not usually considered alongside other genres considered more “scientific,” such as medical, astronomical, and mathematical compilations. In fact, “ambitious magical formularies” are similar to these genres in their effort to compile and organize technical knowledge and have the invaluable advantage of surviving in the form of a considerable corpus of papyri, allowing us to observe scribal practices of compilation and transmission. In this paper I will present a methodology to uncover and understand these ancient practices of compilation – storage, standardization, manipulation and presentation– derived from scribal observation in the magical formularies.