Version Control! If you haven’t used version control before, go check out Subversion. I would also recommend the windows client TortoiseSVN. Honestly, version control has the potential to save your ass by allowing you to revert bad changes. The ability to compare current and past versions of files also makes it an invaluable development tool. Plus a million more things.

As far as the auto-deployment utopia though, version control is key because it allows you to automatically pull the latest versions of files (or the latest stable versions if you prefer) directly to your production server. No hunting around for changed files and uploading via ftp. Plus, in the worst case, if the update breaks the live version of the site, you can easily revert to how it was before.

Compression. One of the goals of good web development is of course to have pages load as quickly as possible. Yahoo offers a fantastic tool call YUI Compressor, which will compress (or minify) CSS and Javascript files to a fraction of their initial size, while maintaining full functionality. It does this by eliminating unnecessary whitespace, optionally renaming variables (in a consistent manner of course), cutting out redundant braces, etc. You obviously wouldn’t want to actually work on the files in this format, but doing it before making them live helps page loads and essentially costs nothing.