The Quick Access Toolbar allows you to quickly add often-used commands to always be available within reach.

To add icons to the custom toolbar, click on the down arrow, and then “Customize” in the drop down menu.

Then, click on the command you wish to add to the Quick Access Toolbar, and click the add button in the center of the box.  The command will shift to the right side of the box, signifying that it will be shown on the toolbar. As the bar is horizontal, the topmost icon will be shown the furthest left on the toolbar. Arrow buttons on the right side of the dialog can change the order of the commands on the right side.

The Toolbar Preview at the bottom of the dialog shows the current selection of the toolbar icons. To accept all changes, click OK.