Start with good beef
Freshly ground meat makes all the difference. If you don't have your own grinder, ask your butcher for a coarse, loose grind of short rib, brisket, and sirloin. Two pounds of ground beef will get you four fat patties.
Gently form balls of meat that weigh 8 ounces each. Try to smooth over deep crevices (cracks allow heat to penetrate the core too quickly) and gently press them into discs about 4 inches wide. They should have air pockets for juices to gather that will keep them tender.