In my view, the templates that come with Microsoft Word (or any other program for that matter) were always provided to get ordinary tasks done quickly. They also serve as great examples of how you can produce great looking documents. However, I think Microsoft Office users in general have taken templates too far. I don't think they were ever supposed to be used as a part of a company's corporate identity.
Take fax cover sheets. How many times have to seen this one?
Probably over a thousand times, right! If it were up to me, this one would be outlawed from further use. However, with 2 simple changes; you can use this template to create a look of your own. First, replace the black block with your logo, and then simply change the font face to something different that goes with your logo.
Small changes like this can be done with all of the templates provided in Microsoft Word to give yourself a unique identity that stands out from others and makes a good impression on your clients. Some take some work to figure out because they're laid out differently than you're used to, but you should be able overcome them with some effort. Besides, you can also just use the templates as a guideline to create your own from scratch.
To make your templates in even more unique, go to the Microsoft Office Online site and use the updated templates there to start with.