It really depends on what I am trying to do at the time and what I am trying to convey to the audience. For instance for a writing prompt I was told to write about a wedding. My first idea would have been a continuation of an episode of a cartoon I watch and that I know my target audience would be familiar with but I tossed the idea because I did not think I could emulate the characters of the show well enough. The second idea was to be a continuation of a popular fanfic of the same series. Again the idea was scrapped but this time because I thought I would be giving out to many spoilers to those who haven't read the fanfic.

Now i'm going with original characters with my own plot. Who knew that pulling together your own idea and implementing it was easier than trying to complement and continue someones work?