Review Minification and Bundling of resources like CSS and Javascript and the tools that are available at the moment for doing it.

Jenkins is a free Continuous Integration tool which can be very useful for writing quality code.

A couple of weeks ago a coworker experienced a serious issue while working with Sitecore Query. He spent a lot of time trying to run a query for an easy search but it was not working. My friend was pretty sure the syntax was well formed but when the query was executed the result was an error: End of string expected at position ##