<snippet>
<content><![CDATA[
This is the snippet body.
Use $1 to move the cursor here on a tab click
$2 is the second place the cursor goes
$3 is the third
${4:default content} here there is some default content.
$0 your cursor moves here after every thing else is done.
]]></content>
<!-- Optional: Set a tabTrigger to define how to trigger the snippet -->
<tabTrigger>newHtml</tabTrigger>
<!-- Optional: Set a scope to limit where the snippet will trigger -->
<scope>text.html.basic</scope>
</snippet>
source.js // Javascript
text.html // HTML
To check the scope of the file you are currently editing, hit ⌃⇧P, and the name of the scope will appear at the bottom left corner.
I keep all my snippets in a folder in Dropbox, and I use a symlink to put that folder inside my ~/Library/Application Support/Sublime Text 3/Packages/User
folder.