You've accumulated some decent samples from your new writing career- but what to do with them? You'll need to arrange those samples into a writing portfolio that is accessible to your potential clients. But how?
Your writing portfolio could (and should) consist of an online element, generally a website or blog. Include a page or entry which showcases some of your best pieces, either via links or via PDFs.
Whether you've produced a magazine article, brochure, or perhaps even a grant application, you should obtain a courtesy copy of the final piece. File this in a nice binder that you can then use to show off your skills to potential clients who are local.
3. Do Overlap Physical Writing Portfolio with Electronic Writing Portfolio
Consider printing off a copy of your electronic pieces for your physical portfolio, and vice versa. Be careful about posting magazine articles online via PDF, though- your editor/publisher may prefer that you email these pieces to potential clients instead of posting them on your website/blog.
4. Do Choose Your Best Pieces
This may go without saying, but think about what "best pieces" means. If you have samples from a recognizable ("big name") client, include it, even if you view another piece as "better." Of course, that doesn't mean you leave off your highest-quality peices. Just select a careful representation of your efforts and client list.
5. Do Promote Your Writing Portfolio
Sure, many employers will ask specifically for your writing portfolio, or links, or samples, but you should also promote it in other ways. If you use sites like Elance or Guru, be sure to include a link to your portfolio in your profile. Include the address at the end of your email.