The most common reason that your ground beef has become dry is that it has been overcooked. As ground beef cooks, the juices will evaporate, meaning that the longer it cooks the less moisture it will have. An easy way to prevent this is by using ground beef that has a higher fat percentage. The higher fat content will keep the beef juicy and flavorful while it cooks all the way through. You can also cover the pan with a lid when it is close to being done to trap some of that moisture until the beef is ready.