Remind them why they need you. Your proposal should immediately remind the prospect of what their problem is and why they are talking to you in the first place. In other words, you should immediately start your proposal off with the pain your prospect is feeling. Are they not making enough sales? Is their message not getting out to their audience? Could their life_savings be in jeopardy? They are talking to you for a reason.
The other design factor aside from the text is the imagery that you can use. Many of the newsletter templates will come equipped with basic clip art or graphics. Others will include areas where you can paste in your own graphs, photographs, or other graphic items that help round out the information. It's important to remember that the first thing that people often look at, even before the headlines, are the images, so make sure that they are strong ones that are eye_catching. Color newsletters also tend to be more appealing than those in black and white, though they can cost a bit more to print.