A writer's portfolio should include a bio that introduces who you are and what type of writing you specialize in. It should also include social links, such as a website or blog, where potential clients can find out more information about your writing. A contact form is also important, as this will allow potential clients to easily get in touch with you with job requests or questions. Finally, you should include samples of your work, such as blog posts, articles, or anything else you've written. This will give potential clients a good idea of your writing style and abilities.