Common Web Design Mistakes that Designers Need to Avoid discusses several essential elements of effective web design that designers should consider to avoid common pitfalls. Specifically, it discusses how a well-organized website with intuitive navigation helps users and is identified by search engines. It also stresses the importance of including relevant images and engaging content to capture visitors' attention and interest them in exploring the site further. Additionally, it notes that a responsive design is crucial for reach given most people use their phones for internet activities. Finally, it provides some SEO best practices like using proper heading tags and optimizing image file sizes for faster site performance.