Spacing between Font Awesome icons
use the fa-fw class:
http://fortawesome.github.io/Font-Awesome/examples/
It's clean, and better than adding a style to your elements.
Just set a margin as you would do for anything else. Pure CSS.
Actually you can use to create a space
<i class="fa fa-home fa-fw"></i> <i class="fa fa-home fa-fw"></i>