It's time for a funny story!
Michelle and I used to work together writing online deals for a local company. After a few months at it, we had developed a voice for them that was so similar almost non of our coworkers could tell who had written which deal. We really should have turned it into a game, because that would have been hilarious.
The funniest part of this story is that a friend of mine had to remind herself that I wasn't the one who wrote Monday's blog post this week. Now, I can't say for sure whether that was because of the writing voice/style or just because of the content, but it made me laugh and start thinking about writing voice.
Your voice is, simply put, the way you write--your humor, your word choice, your typical sentence/paragraph lengths, imagery you pull on again and again, etc. Your voice changes with where you are in your life or career, what project you're working on, and even what books you've read recently. Some changes are bigger than others, obviously, but I don't think anyone's writing voice is ever 100% consistent across everything they've written or are working on.
I think one of the biggest pieces of advice on "finding your writing voice" I've seen is something along the lines of "write like you." Which is great advice, don't get me wrong, and you'll need to eventually figure out what "writing like you" sounds like. But if you're struggling to find your writing voice, or if you're stuck on a project, or for any other reason at all, try mimicry.
By attempting to write like other authors you love, not only are you giving yourself an interesting writing exercise, you're also learning (even if you don't feel like you are) what about those authors' voices pulls you in and makes you excited to read, what flows for you, what works (and, sometimes, what doesn't). It pulls you out of your comfort zone and forces you to pay attention to how you're writing, which can make you more aware of how you use language in your own writing.
Obviously, mimicry isn't the end goal here, but I think it's an underused tool for helping to develop your own voice and your own style. Then again, as someone who came to her own style (you know, as much as there is) through a slightly-obsessive fanfic stage where I tried to get as close to the voice of the source material as possible, I might be a little bit biased.
Emily, thanks to her roommate, has a brand new obsession to not write crappy fanfic about: Elementary. It's a problem. A wonderful problem. She might be slowly getting crushed to death under the weight of her collective fandoms, but all of this input just helps to make her writing voice even more flexible. At least, that's her rationalization.