The hamburger is an American classic and a yardstick of the cookout. Mastering the burger therefor is an aim for every griller to ever own grill tools. What could easily be called the perfect burger is both juicy and flavorful, but still held together well. The real trick to a great hamburger patty has nothing to do with seasoning mixes or even added ingredients at all.
A good burger, full of flavor, is little more than good beef. The more flavor the original meat has logically the more the burger will have. So pick good quality beef, preferably ground by the butcher rather than shipped ground. Pick also an 80/20 mix of lean meat to fat, this may seem like a lot, but quite a bit cooks out when grilled. This balance plus a good amount of mixing just before forming the burgers is all that is really needed apart from salt, pepper, and that wonderful grill flavor. Giving the meat a good mixing before forming it makes the fat present tackier and thus the patties stick together a little better. Some grillers also promote poking a little hole in the center of the burger to let heat flow better, but that is an option every griller can make personally.