010-2011 Drawing Complex Roofs with Vectorworks 2008-2011 (Short Sharp Manuals)

I often find the standard Vectorworks roof will not make the roof I want. If you work on rennovation projects you will find the standard Vectorworks roof will not be able to draw the final roof you want, and sometimes find the standard roof will not draw the existing roof because people have added and extended the building over the years. How can we make Vectorworks do what we want, or is there a way we can help the standard roof do what we want?