cleaning the tongue helps, but most people don't floss everyday as is recommended (actually twice a day). when you don't floss, the food decays in between your teeth and causes bad breath. or for very intense bad breath it could be something internal, a certain type of bacteria in the stomach or something like that. that can be addressed through change in diet or medication. i believe eating fresh parseley is a good natural deterrent to intestinal bad breath. maybe eathing fresh peppermint leaves would help too. but bad breath mostly occurs because of diet and neglected hygiene.