1. Which version and build are you using?
Please let us know which version (1.6.9, 2.1, e.g.) and build (20100810) of ExpressionEngine you are using. Version and build information can be found in the bottom of any control panel page. If you don’t provide this information it will likely be the first question you’re asked. Using the Freelancer version? Make sure to tell us explicitly.
2. Update to the latest build
ExpressionEngine is under constant development. Bugfixes and improvements are constantly added to the code. If you are not on the latest version and build, please try to upgrade first. It just might fix your problem. New builds are announced in dedicated forum for EE 1 and EE 2.
3. Try to test without extensions being a factor.
HowTo Disable Extensions via the Control Panel will give you instructions on disabling your extensions all at once.
4. Know how much memory is allocated to PHP
EEWiki: HowTo Determine Memory Limits
5. Reduce the complexity of your templates
When testing your templates, test in a new template group/template with just enough code to test the concept. If the code works in the abbreviated template, start adding complexity until you figure out where the error/problem is.
6. Don’t post how to questions in the official support forums
Normally how to questions belong in the CodeShare forum. This way other members of the community can assist in helping you find other ways to accomplish a task.
7. Try troubleshooting without removing index.php via .htaccess
If you’re having issues with .htaccess, post in the CodeShare forum. We don’t provide direct support for removing index.php via .htaccess.
8. Test your code in more than one browser
Use one browser for logged in SuperUsers, one for logged in Members, and one for Guests. That way you have three different ways of testing if_logged_in code as well as possible browser bugs.
9. Be specific when describing a problem
Don’t just say it’s slow. *What’s* slow? The front end, the back end, that sort of thing.
10. Know where to obtain support
If you are using third party add-ons, look for support from them. Sometimes the support staff may know an answer, but the responsibility for support lies with the third party author.