Launching an ExpressionEngine site? Check list
When that launch day comes there are numerous things you want to check with the website and here are a few for EE in particular.
Make sure you have an 404 page setup and working. Strict urls were introduced a few years ago by EllisLab because of search engine issues. They make 404 pages easier, however certain modules struggle to work well with them. It is however, in our opine not a problem, whether you are running strict urls or not, a working 404 page is highly recommended.
Caching can speed up pages and sites considerably in certain situations, there are also a number of specific third party add ons that deal with caching, notably Solspace Template Morsels and CE cache. It's a good idea to get caching working from the off, although admittedly this is not an always for our projects. Caching comes into its own on high bandwidth sites, this is where it can work incredibly well.
Make sure your debug=0 are set to zero and not 1. There's a good chance php errors will show on your live site if its the later. Sites can develop problems and you don't want your users seeing mysql and php errors for potential security breach best practises.
htaccess files are will probably be the smallest file on your site, they are however the most powerful and can be incredibly dangerous. One wrong character and your site could be doing very strange things. An htaccess redirect tutorial is well out of the scope of this post but make sure you have your redirects from older pages setup correctly. We always remove index.php from our urls more from a beauty point of view than anything. Having built so many sites it takes us only a few minutes to set up, but its just a better and more user friendly way to set up the urls of an ExpressionEngine site. Some suggest this is an search engine optimisation issue which we don't believe is at all true. There are millions of sites with index.php and far worse in their urls that have high rankings. It's not hindering them at all. Google and the other search engines are more than capable of making sense and not punishing what is a very small matter when it comes to indexing and ranking web pages.