The cut of meat determines how tender or tough it will be. Also if you overcook it, it will be tough. I don't have any luck with the broiler so I do my steaks on the grill unless the weather is too bad in which case I pan fry. The best seasoning I've found is Grillmates steak, basically salt and pepper with a little boost. Cook your steak on high till medium rare, time varies upon thickness.
Are you looking for a marinade for a flank steak or something? What I use for a marinade is a ziplock with soy sauce, olive oil, lemon or lime, dash of worshestire, grated ginger, garlic, a bit of brown sugar and chopped parsley or cilantro. Marinate over night, cook to medium rare. Let the steak rest for ten minutes before thinly slicing against the grain. (If you don't let it rest, you lose all the juiciness)