Toolbars take up valuable screen space, particularly on small screens and laptops, so it would be nice to be able to toggle the most frequently used bars on or off.

Word provides such access to the toolbar for the Drawing tools via the button, but for the others, the route is via a right click in the toolbar to enable you to check the required bar. It is, however very simple to create a macro to toggle the toolbar(s) on or off.

Sub ReviewToolbar()
With CommandBars("Reviewing")
    .Visible = Not .Visible
End With
End Sub

The same method can be used to toggle the merge toolbar as in the second example

Sub MergeBar()
With CommandBars("Mail Merge")
    .Visible = Not .Visible
End With
End Sub

Essentially similar is the method to toggle Text boundaries.

Sub ToggleTextBoundaries()
With ActiveWindow.View
    .ShowTextBoundaries = Not .ShowTextBoundaries
End With
End Sub

For instructions on how to install the macros, checkout the idiot's guide to installation.