Avoid negative headlines. People are literal minded and may remember only the negatives. Sell the positive benefits in your product. Look for emotional words that attract and motivate, like free and new and love. Don't be afraid of long headlines.
Research shows that, on the average, long headlines sell more merchandise than short ones.
Look for story appeal. After the headline, a striking visual in the most effective way to get the reader's attention. Photographs are better than drawings. Look at your advertisement the way it will appear in print. Beautifully mounted layouts are deceptive.