Ho to create paint fabric in PS ?

Hi All,

I am looking for a tutorial that shows how to extend a dress of a fashion photo to show more facric that it actually has. I know I can get photos of fabric and add them by pieces, but I wonder if there is a way to actually fake it by just kind of painting it in. I currently have several photos with wedding dress but I do not have photos of extra fabric in the same type/color/light, hence the question.  

Thanks!