Found this to be very good. I find in writing much like in life you work better when you compartmentalize. I use to do over the phone IT support and I found that if I compartmentalize my feelings after each call, then each caller will still get A+ support.
Much like in writing, when I sit down with my pen and a pad I give myself 5 minutes to deflate from the day. Then I get to work, and if I find that my emotions are getting the best of me I normally highlight the area walk away and come back and reevaluate what I wrote.