How do you properly cook a steak?

You can use the rule of thumb method to measure the "doneness" of the steak: You loosely touch one of your fingers with your thumb depending on how well done you want it, and the tension of the muscle of your hand below the thumb will be the same as how the meat should feel when you press it.

First, let the meat warm to about room temperature. This way you aren't trying to heat up a cold center. Personally I prefer to only cook each side once (meaning I only flip the meat over once). The actual temperature of your grill and the amount of time you cook it per side will depend on the thickness of the steak and how you want it done. Don't use a fork or knife to cut it open while it is grilling as this will let the juices out. http://www.bbqreport.com/archives/barbecue/2005/07/24/how-to-tell-when-a-steak-is-done/ Also, I would argue that medium-well is not a properly cooked steak.

An important part of the process missed by the other answers is allowing the meat to rest for up to ten minutes before before serving (depending on size). This is because at temperature the muscle fibres have tightened up and are unable to retain their juices. A steak straight off the heat and cut open will instantly lose all its juices. If you allow the steak to cool for a few minutes then the muscle fibres relax, hold the juices better and you end up with a much juicer steak with more flavour. Resting meat is a very important part of the cooking process.

Here is the method I use for turning out a perfect steak every time. Pick a quality piece of meat that is approximately 1.5 inches(almost 4cm) thick. Let it sit on the counter-top for 30-45 minutes until it is roughly room temperature. Heat up a cast-iron skillet (or similar) to medium-high. Lightly coat the skillet with an oil that has a high smoke point (grapeseed or coconut oil). Preheat the oven to 500F(260C). Also, put a cookie sheet in the oven during this step too (preferably one that can handle high heat without warping). I like to put a light rub of olive oil on the meat. Then I season it with salt & pepper or garlic salt & pepper (depending on mood). Use TONGS (not a fork) to put the steak into the skillet. Sear each side for 90 seconds. Don't go longer than this. Use the tongs to transfer the steak to the cookie sheet in the oven. Cook each side in the oven for 3 minutes. Place the steak on a plate, put a tablespoon of butter on top of it, and cover it with tin foil. Let it rest for 5-8 minutes. Steak should now be medium rare (about 135F(57C) at center). Serve.

Here's how I grill a steak: Let it thaw completely before attempting to cook it. Set the grill to medium/high heat. Clean the grill by putting an onion on a skewer and using that to clean the bars. It adds flavor and gets the bars clean for a clean cook. For an average thickness steak, I throw it on the grill, close the cover, wait 6 minutes. (closing the cover is very important as it allows the steak to get enough heat. Check for grill marks on the bottom side, if they are there, flip. Grill for 6 minutes on the other side with the cover closed. Use a meat thermometer to check the temp of the meat. Medium is around 140 Fahrenheit (60 Celsius). Using thermometers makes cooking a science! Enjoy! I left out any seasoning or marinating, because this is just how to COOK a steak, not flavor it.

One thing restaurants commonly do that no one has mentioned yet is to grill the steak until it looks right on the outside, then stick it in the oven until it's "done". There's a good chance your grill is just too hot to get the steak perfect.

First, cooking on a very high heat is appropriate only if you want the meat browned on the outside but very rare ("almost totally raw", as the questioner puts it) on the inside. Since this is evidently not what the questioner wants, the first thing to do is to turn down the heat. This will take you a long way towards a great steak: salt both sides just before cooking, and fry on a medium heat in a pan with just a drop of oil. Time depends on thickness of the steak. Second, as Ian Turner points out, turning frequently (once per minute is good) improves the evenness of cooking (and no, it does not dry out the meat). This is also mentioned in McGee's On Food and Cooking (p. 156), which everyone on this site should own. I find that to get good browning with this method you need a higher heat - and the turning means you don't get the burnt-on-the-outside-raw-on-the-inside problem. Finally, always rest your meat - five minutes should do for a steak, 10 won't hurt in a warm environment. This evens out the internal temperature and hence evens out the "doneness". You can test how well done it is either by cutting it open to see (the juice you lose is only local to the cut and won't affect the rest of the meat), or, after some experience, you can tell by touching and feeling how firm the meat it. It's worth practising this touch method.

One approach I've taken from Heston Blumenthal is to keep turning the steak every 20 or 30 seconds. That way the heat travels into the steak a bit more evenly.

So much differing advice - but I'll chip in with my combination (which contains much the same points as others) 1) Always allow the meat to warm to room temperature first 2) Always pat dry the meat (the same holds true for good roast meats too). This even applies if you've marinated the meat (a couple of hours lying in sliced garlic can be nice). 3) Optionally season with black pepper before grilling (season with salt after, if you want salt). I tend to lightly season each steak with a little oil and then grind over some pepper. 4) For a medium-well done steak Griddle for 2 minutes each side on a cast-iron griddle at insane-o-clock heat, then transfer to a warm oven for another 6-8 minutes. (Personally, like many people here, my preference is for a medium-rare steak / black'n'blue - griddling and then simply resting the steak wrapped in foil or under a lid should be enough cooking for medium-rare). 5) Rest for as long as you can stand not eating it. To be honest, I think that the actual cooking technique can vary (you can leave the meat on a grill rather than transfering to oven, but with a griddle it's quite easy to overcook the outside - if you're sticking on the stovetop a flat pan may be better). The two key points are warming the meat first, and letting it rest after (as heat will continue to transfer from the outside to the middle, it actually continues to cook while resting).