Avoid overcooking. Remember, these are thin patties and don't need a lot of time on the heat. 2. Use ground beef with at least 20% fat or more. The more fat the more moist (and flavorful) the patties will be. 3. Make sure the pan/griddle is hot before adding the patties, and patties make full contact with the hot surface of the pan/griddle when smashed down to create a flavorful crust while sealing in the juices.