This will make it easier to conform with your style guides and coding standards by giving you a nice visual reminder of when you are approaching your line length limit.
First, in your
Preferences.sublime-settings file add the following setting:
/* Places a vertical line after character 80. You should use whatever value you tend to use as your length limit most frequently */ "rulers": 
Then, for each language/syntax that you have a different line length limit, modify the syntax-specific settings. For instance, in my
HTML (Twig).sublime-settings I have: