Shaula Evans at 2013-02-17 15:43:39:
> It is inadvisable to attempt a minor plot in a photoplay unless it has a distinct and important bearing on your big story
When I read this what immediately sprang to mind were the romantic subplots that are grafted on to action movies and thrillers that have absolutely no bearing on the main plot at all!
I find that the stories I like best are ones where the subplots arise organically from the internal and external goals of the supporting characters, they affect the protagonist and her/his main goals, and in the end their resolutions are all tied up together.
And my test here is: if you can cut a subplot and the main plot doesn't suffer, the subplot isn't integrated or important enough.