​Choice Meat: Use American beef. Prime is best, but choice is a close second. Highly graded choice is preferable to lowly graded prime, he says. Important: It should be raised naturally with no antibiotics or hormones. 
Marbling: Steak should be well marbled for a tenderer, juicier result. Animals that are "finished" (raised the last 60–90 days) on corn or grain bulk up with fat and produce more highly marbled steaks.
Optimal size: 1–1 1/4 inches thick, 12–16 ounces boneless for a single serving, or shared family style. 
Temperature: Take the steak "from the fridge directly to the grill," he says, to get a crusty exterior and better control the interior. "If a steak is room temperature, it will be harder to cook, especially on a hot day."
Checking doneness: You can press the flesh; medium rare feels like a half-clenched fist (with one finger, press the muscle between the thumb and forefinger on the opposite hand). But this doesn't work well for dry-aged beef, which has 15–20 percent of its moisture removed and naturally has less give, he explains. To be sure, use aninstant-read meat thermometer to test doneness. Medium rare is Lomonaco's preference since meat toughens as it cooks. 
After cooking: Meat continues to cook after it comes off the fire, and the internal temperature can go up another five degrees in five minutes. Also, let the meat rest 7–10 minutes before serving so the juices are redistributed into the interior of the meat.