I've spent a long time trying to make the perfect steak, so here's what I've come to learn, if you can bear the length of this post.
Everyone's preferences will vary, though personally I hate any steak done over medium. I also dislike overly strong flavours, and think just a touch of BBQ sauce is all you should ever need, if the steak is cooked properly.
If you have a PVR, record "BBQ University" by Steve Raichlen. I've learned a lot from his shows, and he's pretty entertaining to watch too. I have a few of his BBQ books also, they're also very helpful.
Something that he can't teach you in a 1/2 hour show, or from a book, is how to "see" where the meat is at inside by looking at the surface. Its a learned skill and I've ruined plenty a hamburger and steak figuring it out. For hamburgers, as a general rule, when you see the juices starting to flow through the top of the meat, you're approaching medium rare to medium. Steaks are a little more complicated depending upon the cut.
Steaks add difficulty, especially if you want to do the perfect thick filet like you get in a restaurant, seared on the outside and a healthy deep pink throughout the inside, with no "red' or cold parts (if its cold, or room temperature, it is blue rare, if it is warm and approaching pinkish, but still more red than pink, rare). I used to always get it way too crispy on the outside, but too cold in the middle. That is a sign of overly high heat. Because I was trying to get the grill marks, I was always keeping the heat too high. Since then, i've learned that a little olive oil goes a long way to making the outside cook darker without wrecking the inside.
I've wrecked a lot of steaks, so trial and error is the best teacher. Just before my "masterpiece" filets last week I ruined two Galloway beef ribeyes the week before by experimenting with red wine vinegar, but I learned a lot in the process
Here's how I did my last filets, and they were perfect, as good as any local restaurant (I say that because Morton's of Chicago still makes the best filet I've ever tasted):
- Get thick cut filets (for other cuts see the end of this post) --- My favorite is the place in Stadium (Bon Ton?)-- though any good butcher will do
-A few hours before they are to go on the grill, take them out of the fridge. Lightly spray them with olive oil (I use a spray bottle, makes for a very thin coat, but you can brush them too), and add a little garlic salt. If you like a stronger flavour, add a little seasoning salt or the pastey steak rub you can buy in the supermarket
-The steaks need to get to room temperature before they go on the grill. If the steaks are coming from the freezer, don't use a microwave to defrost them. Get them out with plenty of time to defrost on their own... though fresh is always better than thawed
-Heat the grill to about 500. Once it hits about 450 to 475, you can back the dials off a bit, and the heat will still go up. Unless you're really good at grilling, without experience you're going to have problems above 550 because the margin for error becomes lower (but you can still make a great thick filet with 550 heat... or even to 600 if you like it blue rare in the middle)
-Here's what I do if I have guests.... I take a plumber's propane torch just before the steaks go on, and heat the grill bars for about 20 seconds. This gives the steaks a real nice grill char, but doesn't cook them deeply, its really just for show. (I also use the torch when I do beer can chicken, dirctly on the chicken just before it comes off the can, it really makes the skin nice and crispy without burning the meat inside...)
-When you lay the steaks down on the hot grill, lay them down in same direction so you can control the char marks with ease. For example, all up to the right: //// (that's meant to look like four steaks in a row

). Close the lid and wait 2 minutes.
-Open the grill, torch the grills where the steaks are going to be flipped to, then flip keeping them all oriented the same way: ////. Close the grill, wait two more minutes
-Open the grill, torch the area where the steaks go next (probably where they were the first time, and flip them, but orient them this way: \\\\. Close the grill, unless you think they're cooking too quickly, in which case leave it open, and wait 2 more minutes.
-Torch the bars again, turn the steaks over, oriented this way: \\\\. Probably leave the grill open at this stage, unless you really think they're waaaaayyyyy too rare.
-After 2 minutes, take the steaks off. They've been on for about 8 minutes.
-Now the part most people ignore: Let them sit, away from the heat, for at least 5 minutes --- don't even let anyone know they're done, because they aren't. They will continue to cook on the inside while cooling on the outside, and the cooling on the outside contributes to their becoming relaxed and more tender.
-You will have 4 filets, with perfectly grilled cross-hatches, cooked just above rare. They'll be delicious, fully cooked about a millimeter in, but deep pink through.
-Never cut the steak to see if its cooked. You'll lose the juices that give the steak its flavour.
-Try to leave the BBQ sauce as an option for your guests-- the better the steak, the less likely they are to use it. Do you ever remember getting a restaurant steak with BBQ sauce already cooked into it? Nope. If you insist on BBQing it in, don't put the sauce on until after the first flip.
-If you're grilling a striploin, rib steak, or some other cut that isn't thick like a tenderloin, cut these times by about 1/2, or turn the heat down (to about 450) and reduce the times mentioned above to about 2/3... but your eyes are a better timer than a stopwatch!
-If you really want to make something tender, and are ready for trial and error, I have a friend who sears the steaks for a minute or so on each side and then grills them for about 30 minutes at low heat. I can't make it work for me, but his results are amazing, and make for a very tender steak. If you have a cut of steak that normally isn't tender, cooking it "low and slow" will help it become tender.
Recap:
First: ////
Flip and: ////
Flip again: \\\\
Final flip: \\\\