Yell all you want, but it's not going to get more of your voice into your writing.
We spend a lot of time helping writers find their voices. It's tough, since school often beats it out of us. That means it only shows up outside of work. (For a fun read, check out this article on regional accents found in Tweets).
I'm not saying you should pepper your business writing with terms like "you'uns" or "a'ight", but I am suggesting that contractions aren't evil and that deft turns of phrase and more conversational pacing will make you tome easier to write -- and read. And if it's easy to read, it's more likely to be understood. Isn't that why you're writing the first place.
Today, bring some attention to the reading you're doing. Look for good examples of voice. What makes it work? Then think about how you could bring more of your own voice and personality to your writing. For extra credit, consider the voice of your business and figure out if the writing that comes out of the company matches that. If it doesn't you've got an opportunity to bring communications in alignment (or reposition the company. (After 24 years in business, I don't think one's necessarily easier than the other -- depends on the organization!)
Meantime, here are some more tips on voice.