Keep it brief, use plenty of white space, avoid tri-folds, use clear and readable fonts, employ colors and rules to balance and highlight things. If you are not experienced at layouts, pay someone who is to lay out your brochure and business card, even if you print it yourself on your own color printer. Author something yourself at least four times a year. You don't have to be brilliant, just clearly informative. Bulletins works great.
Newsletters are more trouble.
The ones you can buy are getting better, but everybody still knows you did not write them. I am talking here about authoring your own thoughts. Let people know that you know something. How are you. Advocates speak or write in support of people and ideas.