Hardware Description Languages and FPGAs make it possible for students to design large, complex circuits. However, HDL-based design is fraught with pitfalls that students often find difficult to understand and avoid. This paper describes a set of design guidelines for HDL-based design taken from a variety of sources and distilled into a concise list. These guidelines are intended to help students avoid these pitfalls and create reliable designs. They have been used in a Senior Design Project course in which students design a wireless network.