So I am going to start a new topic revolving around some useful tips for ASP.NET developers.
The first one is rather simple but very effective. When you are creating your site, it is a good idea to add some tracing to your application for times when you need to debug or troubleshoot a problem. For example, if you are having a performance problem with a particular page, you can turn on Tracing for that page and get a detailed report of how long different steps took for the page to execute.
To use tracing on your site, take a look at: Writing Trace Messages
As you can see there, you can get how long your code took to get from one logged trace statement to the next. This can really help you to narrow down where the bottleneck is that is causing the problem on your site.
There is a great example of this here.
If you are using IIS7, you can use tracing and get that output with your FREB log file, everything you need to set that up is located here.