Adam Grant writes that writing can help in many ways:

In total, well over a hundred experiments have documented the health benefits of disclosing thoughts and feelings about negative events. “When people write,” Pennebaker summarizes in The Secret Life of Pronouns, “healthy changes occur.” Talking into a recorder works just as well as writing, but it’s not effective to express the trauma without language, through mediums such as art, music, and dance. It seems that people need to express the negative experience in words—either through writing or speaking—to reap the health benefits.

The benefits of expressive writing aren’t limited to negative events:

Research by Laura King shows that writing about achieving future goals and dreams can make people happier and healthier. Similarly, there’s plenty of evidence that keeping a gratitude journal can increase happiness and health by making the good things in life more salient. And Jane Dutton and I found that when people doing stressful fundraising jobs kept a journal for a few days about how their work made a difference, they increased their hourly effort by 29% over the next two weeks.

Timing is important:

Expressing thoughts and feelings about a trauma turns out to be most salutary if we wait until we’re ready to start processing it with thoughts as well as emotions.

Timing matters with writing about positive events, too. In one experiment led by Sonja Lyubomirsky, people counted their blessings either once a week or several times per week. Reflecting on good things once a week increased well-being; doing it several times a week didn’t. As the authors speculate, “Perhaps counting their blessings several times a week led people to become bored with the practice, finding it less fresh and meaningful over time.”

Keep a journal or blog:

Journaling is a practice shared across many centuries by icons—not only writers like Virginia Woolf and Mark Twain, but also inventors from da Vinci to Edison, cultural icons such as Pablo Picasso, military leaders such as general George Patton, and political leaders from Washington to Jefferson to Franklin to Truman to Churchill. Along with preserving a record of their ideas and experiences, journaling might have helped them make sense of stressful experiences, focus on their goals, and achieve success. As Virgin mogul Richard Branson writes, “my most essential possession is a standard-sized school notebook.”

This is so true--I find that my weapon of choice is satire, but I've always written. It's always helpful--doesn't matter what it is. A song, a journal, a blog, an article...I always feel I've synthesized something when I'm done whether I use it for something or not. 

It's important to do a little every day.