Part of a freelancer's box of goodies is a portfolio. The portfolio generally consists of client work, although it may also include pieces created for other purposes. My portfolio includes paid content published under the client's byline, paid content published under my byline, and unpaid content published under my byline.
Quite simply, if I'm not paid for the content, then it goes under my byline. Of course, sometimes that byline is my real name and sometime's is a pseudonym. Regardless, the name belongs to yours truly.
When it comes to editing projects, my name seldom receives mention. An editor works behind the scenes. Editors aren't responsible for the creation of the content, we're involved in the improvement of the content. That remains true even if we end up revising and/or rewriting substantial portions of that content. However, a mention in the acknowledgments always brings a smile, because who doesn't like a pat on the back?
Problems come into play when a prospective client requests that content be created especially for him for his project. Such prospective clients use the rationale that they need to see how the ghostwriter will treat his idea. The rule of thumb is to decline such requests--especially when they come from bid platform buyers. The very real risk is that the buyer has no intention of paying for any content, but he'll pick and choose and use that which he likes and still not hire anyone. It happens to many; it happened to me before I learned that lesson the hard way.
Still, sometimes a freelancer takes the risk. Occasionally, that risk pays off. It did so when I applied for a ghostwriting project to adapt a screenplay to a novel. The client intended to shop the finished manuscript to publishers. An occasional, quick search reveals that it hasn't been published yet, although the title and author name could have been changed which would end my search.
Because generating new content for a prospective client is such a risk--as well as a large investment of time, effort, and skill for little promise of reward--the portfolio of previous work serves two main purposes.
First, it shows a body of work that the prospective client can review for suitability. Does the writing meet the client's standard of excellence? Does it appeal to the buyer's taste? Does it show experience or knowledge of the buyer's topic or genre--or at least the capability of the ghostwriter to conduct research to speak with intelligence and authority on the buyer's topic?
Second, it shows a body of work that testifies to the depth and breadth of the ghostwriter's experience. This is a problem all newcomers to any market have: the Catch-22 of needing the job to get experience when the job requires prior experience. Someone, eventually, will have to take a chance on hiring that newcomer.
The prior experience conundrum affects freelancers. Clients want to hire experienced professionals for the low rates charged by novices. Because skill and experience should and usually do command professional rates, experienced professionals cannot compete on price: they must compete through quality.
The project samples in the portfolio should justify the freelancer's rates. It should show a niche expertise or versatility of experience. It should demonstrate evidence of work completed and the skill of which the vendor is capable. Client testimonials or recommendations also serve as evidence of the vendor's skill, but remember that vendors don't usually post negative reviews of their work. For a broader look at public opinion of the vendor's work--whether for a client or his own published content--look at reviews on public forums such as Amazon and Goodreads.
If you're looking to hire a ghostwriter, especially to write fiction, then take a look at the storytelling skills of that vendor. Read that writer's stories. If you like what you read, then that's the vendor for your project. If you like my writing and want something written, contact me.