Your ad should talk to your potential customer, so don't forget about them. Think about what specific needs you fulfill for them. In other words, the ad should inspire the reader on a personal level. Remember the call to action. Think of this as how you close the sale.
Strong graphics make a strong statement.
Keep them focused on your message. Too much in your ad makes it look to busy. You will appear unfocused. Readers will avoid your message. Very often, less is more.