As tabs tend to open inside wrong windows after some time, it would be helpful to store a preset layout in order to go back if things get messed up.
For example, if I am positioned in a run tab in the Output pane and open up a source file by double clicking in the project browser, the source file opens up in the tab in the Output pane instead of the main Editor window

In menu Window, there is the option to Reset Windows, which fixes this bug. But then all my window customizations are lost.
So – I haven’t figured out how to store my current window configuration. A rather nifty solution (e.g. backing up xml files) is acceptable.
Check this related bug on netbeans.org: Source file opens in wrong window panel
According to this post, the Perspective plugin lets you save a window layout (and switch between layouts). Unfortunately it’s quite old (2008), so I’m not sure if it still works with the 7.2 version.