First write like you speak, then write like you write

Do you find it easier to say things than to write them? You should, because speaking is only the first step in writing. I'm not talking about public speaking, just ordinary speaking. For instance, you have an idea for a new product for your company, or a new way for your organization to raise funds. You can easily describe it to a colleague in five minutes, but putting it down on paper as a formal proposal takes hours and hours, and it still never seems to be right.