Getting a perfect, deep-brown sear on your steaks is about more than good looks and bragging rights. That high-temperature browning creates powerful and complex flavors in the meat, and elevates your steak to a whole different level. Getting to that pinnacle of aromatic perfection isn't as hard as you might think.
If the surface of your steak isn't dry when it goes on the grill, it'll steam instead of searing. That's just basic physics, so grab a fresh paper towel and blot up any surface moisture.
Salt draws juices from your steak, then over time they're reabsorbed back into the meat. If you have a head start of at least 45 minutes to an hour -- overnight is even better -- salt the beef ahead of time. Otherwise, salt at the last moment, or the salt will start to draw out the juices and inhibit browning.
Oil helps promote browning in a skillet, and it does the same on your grill. Brush or spray your steaks lightly with oil before setting them over the coals. Better yet, use clarified butter -- purified butter fat with the water and milk solids drained away -- which adds flavor and helps create an exceptionally good crust.
Those dark, crusty grill marks are the tastiest part of your steak, so why settle for only a little bit? If you keep rotating your steak, the hot grill will sear its entire surface, almost like a skillet.
Charcoal cooks partially through the actual heat it radiates, and partly through the high-intensity infrared energy it emits. Gas grills don't do that, unless you shopped for one with a separate "searing grill" that achieves the same effect with a metal or ceramic grid. Some manufacturers offer aftermarket add-on grates that can bring infrared cooking to your existing gas grill.