Masello's eighth rule is one that I stand behind 100%.
Masello notes that throughout literary history, there has been this image of the tortured creative soul. Writers tend to be a depressed lot, he says, and the job of writing can bring a person down by the end of the day. After all, many writers spend their time alone in a room, brooding. (Hm. Maybe those writers should get themselves to Starbucks.)
Anyway, because of this image of the depressed writer, there is a theory that writers who mess with their mood may also affect their wellspring of creativity. (This isn't just limited to depression; Isaac Asimov had severe acrophobia, but refused to be treated for it partly because he worried that a cure might adversely affect his ability to write.) Consequently, many writers who might seek out treatment for their condition instead leave it alone, almost nursing their depression as if it's something to be nurtured and then tapped into to create brilliant works of fiction.
Masello rejects this completely. Depression, he says, doesn't help your art, but hurts it. It leeches your productivity and can ruin your life. His advice: do what you have to do to cheer up, whether it's taking the appropriate medication or going out with some friends. Your writing will be better because of it.
I'm on the same page as he is with this one. Personal, ongoing misery and depression are not good sources of inspiration. Bad experiences may very well be; many of us take what happens to us in life and eventually put it on the page. But living one's life day to day in a depressed mood, and thinking that you need to feel that way to be creative...reject that notion. No work of art is worth the price of personal misery, especially not in this day and age.
Here's hoping you're all in a good mood and feeling productive.