I'm an ugly girl, My face makes you hurl, Sad I have it, I should bag it. Acne everywhere, Unwanted facial hair. I'm a relation to Frankenstein's creation.
In fact, when I come up with an idea for a parody I try to resist the urge to Google the idea to see if someone has done it already because the answer is almost always, "Yes, of course they have, they've thought of it!"
It becomes more important to me as time goes on to make every album the best thing I've ever done, so it's a lot of self-imposed pressure that also kind of slows me down a bit.
I like to think that I've gotten better at what I do. I spend more time and pay more attention to detail album after album. But pretty much it's stayed the same.
So that's why one of my rules of parody writing is that it's gotta be funny regardless of whether you know the source material. It has to work on its own merit.
At this point I've got a bit of a track record. So people realize that when 'Weird Al' wants to go parody, it's not meant to make them look bad... it's meant to be a tribute.
My own personal tastes don't really have an effect on whether song is a parody target or not. But having said that, I try to pick songs that I actually like because I realize that I have to live with these songs for a long time, from when I'm working on them in the studio to possibly playing them onstage for the rest of my life. So I try not to pick songs that I know would drive me crazy.