This work is intended to provide practitioners in the fields of optical engineering and optomechanical design with a comprehensive understanding of the principal ways in which optical components such as lenses, windows, filters, shells, domes, prisms, and mirrors of all sizes typically are mounted in optical instruments. It also addresses the advantages and disadvantages of various mooting arrangements and provides some analytical tools that can be used to evaluate and compare different optomechanical designs. The presentation includes the theoretical background for some of these tools and cites the sources for the most of the equations listed. Each section contains an illustrated discussion of the technology involved and, wherever feasible, one or more worked-out practical examples.