Since 1979, the U.S. Army Research Laboratory (ARL) has been developing and distributing the U.S. Army Ballistic Research Laboratory - Computer-Aided Design (BRL-CAD) constructive solid geometry (CSG) modeling package for a wide range of military and industrial applications. The package includes a large collection of tools and utilities including an interactive geometry editor, ray tracing and generic frame buffer libraries, network-distributed image processing/ signal-processing capabilities, and an embedded scripting language. As part of this effort, a multivolume tutorial series is under development to assist users with the many features of the BRL-CAD package. Volume I provides an overview of the package contents and installation (Butler and Edwards, 2002). Volume II addresses the basic features and functionality of the package's Multi-Device Geometry Editor (MGED) and offers a comprehensive list of the user commands available (Butler et al., 2001). The purpose of Volume III is to discuss the components of the modeling process and suggest principles for maximizing the effectiveness of BRL-CAD's capabilities. Because of the large diversity in modeling projects, these principles have largely been kept to a general nature so that they have the widest applicability possible. In addition, several appendices have been included to offer detailed discussions on several BRL-CAD tools and features, including the pipe primitive (Appendix A), the projection shader (Appendix B), the extruded bitmap primitive (Appendix C), the .mgedrc file (Appendix D), the Build Pattern tool (Appendix E), and the build_region command (Appendix F). Future volumes in the tutorial series are planned to discuss geometry format conversion, advanced modeling features, and programming options.