As a web and graphic designer, there are a few options to choose in creating a portfolio, a tangible printed version, and an online version. A tangible version, like a printed copy would include quality prints of your best work as a visual example. An online version, is where you can create a website to place your work.
A website is the most popular of the two and allows your potential client a way to privately view your work and give references of what they like of your work that you can incorporate into their project. Your portfolio should be the best of your work, not everything. Of course, you might get the urge to archive your work, but with time, some of your past work may not be considered the best.
Here are some things you should consider when creating your own portfolio:
1. Invest in your own webhosting space for your portfolio. Do not use a free host. You will have more control over your material and you will be able to harness the tools you need to give your portfolio the look you want. In a way, even freelancing, you are conducting a business and you should invest some to put forth your best effort.
2. Quality Images. If you make logos or banners, show your best. Be critical of your past and current work, and display those that will shows your talent.
3. Screenshots of websites you designed are great and even better, a list of websites too. Even if you only did minor work, list the job and the site.
4. If you offer other abilities like Search Engine Optimization, Marketing, or if you write articles, show examples or explanations of these talents.
5. Organize your portfolio so it is easy to get around. Do not stick everything together as it will look cluttered.
6. It is optional to post your resume, but post it with care, omitting information you do not want directly visible to the public. Your portfolio should speak for itself, but if you have gone to school, or have been employed in a related company to your skills, at least be prepared to offer the option of sharing an official resume.
Any other tips you might recommend? Are there actually any free services that might be good for design portfolios? Despite the first tip, I am unaware of any free sources that have yet to impress me as a place to recommend.