Changing a few settings in IIS, optimizing HTML, CSS and JavaScript layout, and applying simple C# rules can lead to increased ASP.NET website performance. Tools like Chrome Developer Tools, YSlow, Google PageSpeed Insights and Fiddler can help optimize aspects like compression, caching, headers and static/dynamic content. Optimizing content delivery includes techniques like putting CSS at the top, JavaScript at the bottom, bundling/minification, using CDNs and removing etags.