Don't add boilerplate code, polyfills, shivs, frameworks and other things that increase the weight of your site unless you actually need it.
How to stop TextMate's Wrap Word / Selection as Link command from automatically downloading the linked page and inserting its title as a title attribute on the link.
The Zen Coding plugin, available for TextMate and several other editors, speeds up your HTML and CSS coding.
If a Subversion repository has moved to a new location, use the svn switch command with the --relocate switch to make the working copy point to the repository's new URL.
Using version control to keep track of changes to your files will make you sleep better at night, and getting started is easier than you may think it is.
Twelve tips that help you use TextMate more efficiently and remove some of the tedious parts of writing client-side code.
To save keystrokes and speed up development I have created a DOMAssistant bundle for TextMate.
Chris Heilmann talks about what causes the code on Web projects to grow out of control.