A quick bath in a brine -- just salt and water -- before your corn hits the grill can vastly improve its texture and flavour, which is saying a lot, since grilled corn is already delicious. Image from wcowperthwaite.
For every four to six ears of corn, dissolve a quarter-cup of salt in 3.75L of water. You can also mix in other spices, like peppercorns or smashed garlic, to add more layers of flavour. Put the shucked corn in a container big enough to hold enough water so that the ears are covered, and let sit for 30 to 60 minutes. Make sure you take it out promptly though: Leaving your corn in the brine longer than an hour can dry it out, the opposite of what you want. The spices from the brine will spread between the kernels, and the salt tenderises them, all of which makes the finished dish, post-grilling, even more delicious.
The Most Important Tip for Great Grilled Corn [The Kitchn]