Although surveys have shown that charcoal is more popular, I want to taste the meat, not the grill. As a result, I prefer a iron/steel skillet on an electric element. Propane is my second choice. I know, heresey.
It wasn't always that way...
Back in 2001, I decided to host a bbq for our employees on my charcoal grill. I don't remember having any difficulties with getting the coals ready but there was a problem nevertheless. When we sat down to eat, the engineer (Mike) took one bite and said, "this tastes like wine, I can eat this!" We all took a few bites to comfirm what he was saying. Sure enough, somehow there was a strong taste of lighter fluid in the meat. Now, I had used lighter fluid on the charcoal, and I did wait for the coals to turn white and then put the grill over the coals. I really have no explanation why the flavor was so strong. I assume that some fluid fell outside the fire and the vapors got in the meat. For the next couple of days, several us where burping up lighter fluid taste. Nasty. This has made me more sensitive to the flavors imparted by a charcoal grill.
Charcoal is usually prefered by many people I think because of the smokey flavors, etc. Flame cooking also sears the meat differently than a hot plate.
I have grilled using charcoal many times since (as recently as the phx gt last week), and people tell me they can't taste any lighter fluid (I check!) but I can smell it and the meat has that sticky sweet burned flavor.
Now you should know I am not an expert on cooking and don't get paid to be. I am sure not all my methods are the best, I am still learning. I mostly look for methods that don't take a lot of time and produce safe but reasonably tasty meat. To be really sure that the meat is cooked, you need to cut it open or at least probe it in several places with a meat thermometer.
When I cook hamburger, I cook the first side at high heat to sear the outside and create a fluid barrier. I then flip the meat. After a minute or two, I turn the heat down (or move the meat to the cool side of the grill) and slow cook it. When the core heats up, you'll see small dots of blood appear on the top of the meat. When that runs clear, the meat is well done. Usually the fluid thickens on the surface and forms dross on the top of the meat, I scrap off any large chunks and flip the burger one more time for a quick sear. This is mostly to clean off the patty. I never squeeze the meat (you want it juicy, not dry) and my intention is never to have any pink in the patty since I usually cook for other people and don't want anyone to get sick.
I normally don't add any flavors on the grill but sometimes people ask for sauces, seasons salts, etc.
Some people prefer to use lean meat (~5% fat). With meat that lean, it becomes more critical to keep what fat you do have in the meat. It is a key component in the flavor. Also, the fluids are going to be more scarce so either you have to watch it more closely or use another method to check the temp.
For steak, the technique is similiar to hamburger but I stop cooking it soon after the blood starts to seep out the top. I prefer my steaks medium rare (a layer of pink through the middle). The desired flavor is "tangy". I then can add worchester or A-1.
I have used other techniques for testing when the meat is cooked such as meat thermometers, poking the meat, cutting it open, etc. But usally, just watching the fluids will do the job. I make sure I have a nice white light handy (1x123 LS) for checking the colors. Some people use a headlamp so they have both hands free and don't get their light sticky.
For chicken, I try to be extra carefull so people don't get sick. I tend to cook it slower, and cut in two the largest piece on the grill to test. It should be white all the way through, no blood and no pink. I tend to prefer chicken that has been marinated (put it in a ziplock bag with italian dressing for half the day or more in the fridge).
Protect those eyebrows...
Peter