All my life I've looked at words as if I was seeing them for the first time.Ernest Hemingway
Of all the effects that you attempt as a writer, 'voice' is the most important and the most elusive.
Writing always sounds like something. Think of your writing voice as a version of your amplified singing voice. Rhythm, theme, sound, crescendo, reprise, and composition are also effects of writing.
Voice represents how often you use metaphors and figures of speech. The length and structure of your typical sentence. If your words sound dispassionate or partisan. If you write plainly to invite in all types of readers or with a slang for an exclusive club.
Voice is your identity as a writer. It's integral to your writing and not an add on. Make it distinctive. Be authentic.
Develop your own unique voice
To develop your own voice, pay attention to writers who you relate to you on websites, blogs, and social networks. Does the writer sound playful or serious?
Try to ditch an assertive voice for a playful voice. A smiling voice. That will serve you for the most of the time. A playful voice denotes exuberance, laughter, fun, and entertainment.
You can also think of yourself as a DJ-mixing tracks. The more music you have to sample from, the more records you have to spin, the more likely you'll keep your audience dancing.
You can use voice to control the mood, calm it down, or raise it to a crescendo. But always keep changing, varying, evolving your voice so it seems fresh and immediate and keeps the reader hooked.
Style is not the same as voice. They're subtly different. Style is what creates a mood. It has a hypnotic feel to it. You might adapt your style based on what you're writing. Voice is more durable. It's an integral quality of a writer. Something that comes from within. Style is an external quality.
Do you use 'I' to create a familiar voice? Or, 'we' to express the collective? Or 'you' to sound conversational? Or 'they' to seem detached?
Writing in the first person carries the greatest authority because you're assuming responsibility for what you're writing. The trouble is that readers recoil from the pronoun 'I' because it reminds them that they are not experiencing what's written. The fix is to use first person but submerge the 'I'. Instead of "I heard the bells ring" say "The bells rang" or the "The bells began to ring". Write in the 1st person but weed out all the pesky I's.
Create an alternative online identity. Give your digital doppelganger a name and a writing voice that's distinct from yours. See what you learn. Make a list of adjectives that would define your voice. Like heavy, tentative, and aggressive. Use these to change your voice and style.