I needed to add font awesome arrows to a jQuery.tablesorter table.  The css was a bit tricky and I don’t want to lose it.

    table.tablesorter thead tr th.headerSortUp:after,
    table.tablesorter thead tr th.headerSortDown:after,
    table.tablesorter thead tr th.header:after {
      font-family: FontAwesome;
    }
    table.tablesorter thead tr th.header:after {
      content: "\f0dc";
    }
    table.tablesorter thead tr th.headerSortUp:after {
      content: "\f0de";
    }
    table.tablesorter thead tr th.headerSortDown:after {
      content: "\f0dd";
    }

<table id="table" class="table tablesorter">
    <thead>
        <tr>
            <th>Header 1</th>
            <th>Header 2</th>
            <th>Header 3</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>Data 1</td>
        </tr>
        <tr>
            <td>Data 2</td>
        </tr>
        <tr>
            <td>Data 3</td>
        </tr>
    </tbody>
</table>