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.
One option that many people don't think about is to use an article template. An article template gives you a general idea and then you have to insert the topic using the idea they suggest. For example an idea would be Methods for Saving X and a topic would be Methods for Saving Money. With most templates you will have the ability to do at least two articles from it until you can come up with more topics. The two articles would be a positive and negative or upside and downside. There are a number of places you can visit for article templates. Some of them supply free templates while others charge a fee for them. You'll want to do a Google search to see what you can find and use for your articles.