Easily setup and follow a grid based design. Check out gridulator.com
The $gw-column and $gw-gutter variables must be defined in your base stylesheet to properly use the grid-width function.
{% highlight scss %}
$gw-column: 100px; // Column Width
$gw-gutter: 40px; // Gutter Width
div {
width: grid-width(4); // returns 520px;
margin-left: $gw-gutter; // returns 40px;
}
{% endhighlight %}