Finding a grind with the right meat/fat ratio is the key to a good burger and that rich, beefy flavor. Ask your butcher for 50% trimmed brisket and 50% prime tenderloin chain meat. (This is the side meat attached to the tenderloin often used as "tips"). Substitution option: 50% brisket and 50% untrimmed prime skirt.
Be gentle. Gather seasoned meat into a ball and let it sit at room temperature for 4-5 minutes. This allows the meat juices to bind. If you have a large jar lid, use it as a mold by pressing the meat into it to create a perfectly round patty without handling the meat too much. This will also keep the edges from cracking because it applies consistent pressure throughout the patty.
Over a hot grill, the cooking time for a ⅓ lb. burger is two and a half minutes per side for medium. (Make any adjustment from that formula.) Add a slice of American cheese to the burger during the last minute of the second side flip and let it melt down into a dome, covering the burger.
Buns & Topping
It might take a bit of a search to find the right bun because that squishy six-pack from the supermarket can't stand up to a good burger's juices. A good bun should be "substantial" but not overly-bready because then you lose the taste of the burger. Brioche or potato buns are two solid (and readily available) options.
Use a mixture of ketchup and mayo, in a 1-2 ratio (with some chopped pickles and onions or even some chopped jalapenos if you prefer a little “kick”). Spread on the top inside half of the bun and layer over your burger pile, pressing down lightly to seal the deal.