Creating a SharePoint 2010 master page for a custom footer is very easy to do. Follow these simple steps to make a custom footer for your site.

For this exercise, we will be using a Publishing site. The difference between a Publishing site and a team site is the added layer of checking in/out files before publishing or previewing a live version. If you are not using a Publishing site, please disregard the related steps below.

1. Copy Master Page
   1. Open site using SharePoint Designer 2010
   2. Click Master Pages in the left navigation pane
   3. Right click v4.master and select Copy, then paste
2. Rename the New Master Page
   1. From the Ribbon, click Rename
   2. Type “Customfooter.master” (or any other name you choose)
      
3. Edit the CSS Inline
   1. From the Ribbon, click Check Out
   2. Then, click Edit File
   3. Select Split View
   4. In code, find: <SharePoint:DeveloperDashboard runat=”server”/>.
   5. Add the following code just below the code listed above:
      <div class=”s4-notdlg” style=”clear: both; background-color: #FEAD30; padding: 10px;”> © Copyright XXXX 2013, All Rights Reserved </div>
   6. Click Save. If prompted, click Yes to overwrite existing site definition.
4. Apply Default Master Page
   1. Click Master Pages from left navigation pane
   2. Select the row for Customfooter.master (or whatever you named your new file), BUT NOT the title itself.
   3. From the Ribbon, click Set to Default.
   4. Then, click Check In.
5. View Your Changes
   1. Click Save
   2. Open site in browser, or click Preview in Browser

This information is shared courtesy of a fellow colleague, Larry Cureton. Follow him on Twitter (@llcureton) for more SharePoint related insight.