Brush your tongue. Your tongue harbors bacteria, so carefully brushing it may help reduce odors. People who have a coated tongue from a significant overgrowth of bacteria (from smoking or dry mouth, for example) may benefit from using a tongue scraper. Or use a toothbrush that has a built-in tongue cleaner.
Schedule regular dental checkups. See your dentist on a regular basis — generally once or twice a year — to have your teeth or dentures examined and cleaned.