The single most useful tool for any grilling maven is a really accurate meat thermometer. We keep two thermometers on hand for two styles of cooking. For large format meats or whole birds, which are harder to read, we love the MEATER wireless meat thermometer with Bluetooth and WiFi and a 165-foot range. Just pop the thermometer into the thickest part of your protein and connect it to the app on your phone and you don't need to constantly test and babysit the meat. For faster cooks or smaller portions, we want a super-fast digital thermometer to give us accurate reads, and the Lavatools Javelin has the added benefit of a backlit display for those post-sunset cooks.
Buy it: MEATER+ Meat Thermometer ($99.99), amazon.com
Buy it: Lavatools Javelin PRO Thermometer ($55.99), amazon.com