You want to make sure the bristles of the brush get underneath the gums. Turn your brush to a 45 degree angle and brush along the gum line using a gentle touch. You don't have to use a lot of pressure. Go around and around in a very gentle circular motion concentrating on all of the tooth surfaces. Something that a lot of people forget is that you really should be brushing your tongue as well. Brushing your tongue can help to remove the bacteria that cause bad breath. It's also important to brush twice a day and to use a toothpaste containing fluoride to help prevent tooth decay.