Most popular (and unpopular, for that matter) open source projects would probably appreciate someone who wants to write high quality documentation. A good appr

Most popular (and unpopular, for that matter) open source projects would probably appreciate someone who wants to write high quality documentation. A good approach might be to find some projects you're interested in on Github, and contact them to ask if they'd be interested in someone adding to/improving their documentation and project wiki. I suspect you'll find projects interested in this rather quickly. Then, contributing will be as easy as making a pull request. And that way, any potential employers or clients can easily verify that you've actually done the work you claim you've done by looking at your Github commit history.