"Own work" should not be pre-selected in the Upload Wizard and potentially other upload tools. We get lots of copyright violations that are marked as "own work" at Commons. This makes it easy to just "click through" the Wizard, without bothering to think about this issue. Selecting "own work" should always be a conscious choice.
Additionally, since by far the most common copyright violation is grabbing an image from the web, I'd propose to add "This file was found on the net." as a third option to "own work" and "not own work" with additional guidance for those cases.