There are 3 ways to arrange that:
So how do you choose?
Use method 1 (insert a tag) or method 3 (framework plugin) if:
you want live reloading for sites open on iPhone, iPod, iPad devices or iOS simulator (and, soon, Android devices/emulators)
you want live reloading for sites open on other computers on your network without browser extensions installed
you want to work with file: URLs in Safari (because Safari prohibits extensions from accessing file: URLs under any circumstances)
Use method 2 (browser extension) if:
you want to preview CSS changes against a live site
you want to use the upcoming “saving CSS changes from web inspector” feature
most people prefer this method because it requires no changes to your projects
You can use both if you need to; the script tag you add manually will happily cooperate with the browser extension.
Ready to act? See one of these articles for detailed instructions: