- Install the package via Package Control (it works with ST3, don't worry).
- Create a new file called
default_file_type.sublime-settingsand paste the following:
{
"default_new_file_syntax" : "Packages/HTML/HTML.tmLanguage",
"use_current_file_syntax" : false
}- Change the default language, if necessary (they're usually named pretty logically).
- Save it to your
Packages/Userfolder. This can be found by going to "Browse Packages" via the menu bar. - Restart Sublime for good measure.
Note: Play around with setting use_current_file_syntax to true. I have set it to false here to avoid any potential installation confusion ("I hit ⌘ + N and it's still "Plain Text". What gives?!?). Setting it to true is a very handy feature.