When I began writing daily at the end of 2008, I anticipated that "journal" writing would be the least expensive and most helpful exercise in self-discovery I'd ever done. It was. I am not the first to notice writing's therapeutic effects, of course.
If you haven't yet tried this kind of writing, I recommend it. I always use the back side of the paper that jams in the printer or the pages of e-mail with nothing but lists of addresses. This is not "formal" or "structured" writing you'll want to keep forever. Rather, it is more like a running record of what's important to you on any given day. Some days, for instance, you might write about what's going on--a relative's birthday, a family get-together, a movie you saw, a book you read--and other days you might wax philosophical, or even theological. Or, you might write about your resolve never to set foot in Wal-Mart again, or how much you hate your friend's new hairstyle. Whatever.
Since there aren't really any rules and you aren't going to keep this junk anyway, you have just set up the perfect "no-pressure" situation, which is probably why a journal like this works so well. Journal-writing makes a great warm-up for any structured story- or article-writing that you do. It also can serve as your writing "minimum" on days when you have a lot going on. I began with ten-minute timed sessions and worked up to 40 minutes.
Once I had written like this for a month or more and then began to read back over it (with a highlighter to mark any ideas that might be useful in a story or article), I discovered how fickle my moods were, how changeable I was from day to day, but also how certain themes kept repeating themselves. I was not aware of this as I wrote.
I've learned things about myself I never would have believed if someone had told me (they tried) and could never have discovered if I had not been writing regularly over time. There are other benefits too, but they must await another post.