When we talk about the "you-focus" of business and professional writing, we mean that good communicators use rhetorical strategies and language choices that place the readers' interests and perspectives foremost. We've all encountered situations where someone giving us directions tells us "You can't miss it;" then we have trouble finding the destination. Why? Because the direction-giver, probably, was "me-focused;" he knew where he was sending you, and forgot that you might not know some of the things he did (like "the deli where the church used to be" or "the house that used to be pink").
Consider how "you-focus" can change the impact of a document. Remember this memo you read when learning to cut lard? Now look at the revised version the author sent out.He took into account his purpose, his audience's likely reaction, and his persuasive strategies, and revised accordingly. He not only cut almost 50% of the length, but he changed the impact the document had by using language choices and strategies that made his audience more likely to accept the new policy. He focused it on what the employees wanted--fairness--and in doing so, created a psychological incentive for them to agree with the new policy.
When you revise a document, pay special attention to how you are addressing the knowledge, needs, and issues your audience has. Try to look at the content from the readers' point of view and construct your strategy to best meet your readers' needs--before your own. This is one of the greatest challenges in WRIT 465 and takes practice, but once you master the skill of revising for you-focus, you'll find that your communication effectiveness improves considerably.
See: BWC, p. 281-82.