This chapter overviews the production, study, control, and applications of cold molecular beams. First, we motivate the need to produce cold samples of molecules. Then, in Sect. 3.2, we discuss the primary workhorse of our experiments, the cryogenic buffer gas beam (CBGB). We provide both specific details on the beam source used for much of this thesis, as well as providing an overview of cryogenic buffer gas cooling. We also provide a discussion of beam diagnostics, namely absorption and fluorescence spectroscopy, including relevant equations. Then, in Sect. 3.3, we discuss novel work performed in this thesis on driving chemical reactions with laser excitation. This results in an order-of-magnitude enhancement of the molecular yield in our CBGBs. We characterize the chemical enhancement in detail, and discuss applications. Optically driven chemical enhancement is an invaluable tool in our lab and in other labs working with cold alkaline-earth (like) metal hydroxide molecules.