I journal in the mornings about the previous day, but limit the writing to one page. The one page limit makes it manageable and doing it after a night's sleep prevents it from being just venting, it helps me see the big picture. I tend to write when I'm waiting for coffee to finish brewing, its worth the time.
It ends up being a mix of personal and work things, but it is really helpful as a freelancer when I go back to work for or with people I've worked with before. I can see what was frustrating, where I grew, what was a surprise, what I need to work on, and reminds me when I should just say no to certain situations or opportunities. There is certainly the release factor that the article mentions, but I value it as a way to see patterns and to grow from my own assessment of what worked or what didn't.
In order for this to be beneficial I have to really focus on my part in things, in the things that I can control, rather than on other people's work. You can only write a complain about something three days in a row before you sit back and say, "wait this is familiar, is there something I'm doing wrong, is there another possibility here I'm just not seeing?"
Anyone else do something similar?