How can freelancers maintain originality in creative writing while meeting client expectations?

I find it easy to adapt to the style laid down by a client, and strive to retain the integrity of their voice and vision. Really, though, the best way to remain original is to write truthfully - nobody can write like you, because there's only one you in the universe. I don't impose my personal style on a project when working on Fiverr (unless asked to), but filtering that through what a client's voice is the key to getting a unique, original, piece of work. 

One of the first lessons in creative writing is how to be an effective chameleon—modeling your work after those who inspire you to develop a unique style. This style will eventually be what clients come looking for, but working professionally in creative writing also means endless variety.

There really is no way to guess what kind of project will come across your desk or who will approach you next. Whether crafting brand content, a novel, short story, movie, game, or comic script, the first goal is to build a relationship with the client and determine their expectations. Some clients have everything mapped out and just need your talent in execution, while others are in the early stages of development.

One project may encourage your unique style, and another may have you adhere to that first lesson: being a chameleon. Some clients have poured hours into creating worlds and backstories—that style might not immediately mesh with yours, but the goal is to see how they can coalesce. How can you be tonally consistent? How can you use the tools you've garnered to express the story they've been dreaming of? How can your style help elevate this project without diminishing its voice? 

The joy of working professionally in creative writing is that you'll often get a wonderful mixture of both—projects that unleash your unique creativity and projects that challenge you to funnel that creativity through a client's vision. Both are valuable, and all projects help you grow as a writer.