i like to marinate before frying a steak. it keeps it from tasting oily.
my favorite is a half and half mix of dark beer and soy sauce, with a few cloves of chopped garlic and about half of a chopped onion. soak at least 4 hours, but overnight is better.
then, you can melt a little butter or heat some olive oil in a pan, but i like to keep the heat low. just throw the steaks in and the magic takes over. it takes a little longer, but the slow frying insures that you won't burn the edges. you can sear them on high heat first, but i've never found that to be necessary.
that particular marinade cooks down into a lovely sauce, by the way, which is helpful if you have a tough or dry cut of meat. just simmer it for 15-20 minutes. and don't forget to stir. you can also strain it to retrieve the onions and garlic, give them a little swish in the pan when the steaks are done and use them as toppers.