Try not to make your paragraphs longer than 3 or 4 lines. When your paragraphs are short, people will read them easily. But if they are long, it will seem overwhelming to people. The colors you use in your newsletter design is important as well. So you should know a little about colors psychology. It's not hard. You must already know about the effect of every color on people, before designing or choosing your newsletter template.
After the Cover Letter and Title Page, add topic pages to show that you understand the position and needs of your boss or prospective client. If your proposal is complex, you might need to begin this section with a brief summary_a page or two that states the most important points you will describe in detail in the following pages. This sort of summary is called an Executive Summary for corporate clients or a Client Summary in a less formal proposal. Your goal in this section is to describe the needs, goals, and desires of your client (i.e., the person who will make the decision about whether or not to accept your proposal). This is not yet the place to talk about what you want to offer. In this section, you must demonstrate that you understand the other party's position and requirements.