When you have to fill up the rest of the page

I've noticed that I often run into the same problem in many projects I work on: It seems like I always end up having that extra space that I have nothing to fill up with.

It usually ends up with an additional space that I have absolutely nothing useful I could put in.

What would you do in this case? would you just put whatever comes to mind just to fill up the empty space? or would you restructure the page so there are no empty spaces?