Optimizing icon-fonts CSS size

When using an icon fonts, you usually take a pack of hundreds of icons resulting in hundreds of CSS lines.

This methods allows you to only output the CSS you need.

1. By default, all icons are disabled
2. When you need an icon, you set the 3rd parameter of its list to "true"
3. This outputs only the CSS for icons you need

$icons: (star, '\f005', true), (star-empty, '\f006', false);

Outputs:

.font-awesome-star:before { content: '\f005' }

This isn't limited to Font Awesome, you can do this for pretty much any font you want. You only have to make the $icons list, but it's pretty easy with an IDE like Sublime Text.