There are two basic methods to test for how done your meat is while you are cooking it.
The problem with the meat thermometer is that when you poke a hole into the meat with a thermometer, it can let juices escape that you would rather have stay in the meat. For this reason, most experienced cooks rely on a “finger test” method,
Test for steak doneness by pressing a finger into the meat.
Rare feels like your chin
Medium like the tip of your nose
Well done feels like your forehead
Tip – Let steaks sit for 10 minutes after they come off the grill so the juices have time to redistribute
Tip – Meat should be blotted dry with paper towels before it meets the heat. If not it’s boiling, steaming and braising – not grilling.
Reference – Meat & Seafood Internal Temperature Cooking Chart