This TSP Symposium 2014 presentation explains that projects, testing programs, and testers often fall into commonly occurring testing pitfalls that make testing unnecessarily less effective at uncovering defects, less efficient in terms of testing resources, and more frustrating to testing stakeholders. Based on the experience of many testers, we have developed a taxonomy of 145 common testing pitfalls organized into 21 categories. Each pitfall has been analyzed and documented in terms of title, identifier, description, potential applicability, characteristic symptoms, potential negative consequences, potential causes, recommendations, and related pitfalls. The first 92 pitfalls were documented in the book Common System and Software Testing Pitfalls: How to Prevent and Mitigate Them. Since the book manuscript was baselined for publication, a further 35 pitfalls and four pitfall categories have been identified, analyzed, and documented.