Attracting new editors

Thats the direction, I would go. Something like: "Articles of this kind typically have the following sections (aaa,bbb,ccc) which are missing here still. You can create one automatically by clicking on the titles." as a drop down option list right beside the edit button maybe.

So the idea is: having more different editing options. Even something as simple as an automatic "add an image" where you do not have to place it, but is sorted in a standard gallery beneath the articels' text and is then sorted out later by other editors. This way adding images or creating sections in articels could be made more easy.

The other idea about advertisement for the edit button. I am not sure, if people really do not know that they can edit every page in Wikipedia. But its worth a try.