1. Allow steak to come to room temperature. If the meat is cold when you put it in the pan, It will cause condensation to form on the outside which will prevent browning. Cold meat will also cook quicker on the outside while the inside will remain underdone.
2. Blot the steak on paper towels before placing it in the pan.
3. Make sure your pan is smoking hot before placing the steak in it. Cast iron is best (either flat or a grill pan), but a steak can be seared in most any heavy bottom skillet.
4. Put the steak in the hot pan and avoid turning it unti a nice crust begins to form and the steak naturally releases itself from the pan. If the steak is sticking, it's not ready to turn. Flip the steak and sear the second side. The entire searing process should take about 2-3 minutes.
5. Have your oven preheated to 450 degrees. Place the pan with the steak in the oven for about 6 minutes for medium rare.
6. The easiest way to tell the doneness of a steak is by touching it. Different degrees of steak feel differently. Touch the tip of your thumb to the tip of your index finger. Now feel the area between your thumb and index finger. That is how rare steak should feel. Now touch your thumb and your middle finger. That is medium rare. Now touch your thumb to your ring finger. That is medium. Finally, touch your thumb to your pinky. That is well done.
7. Never, EVER cut into a steak as soon as it comes out of the pan or off the grill. Steak must rest for about 10 minutes. This allows the fibers of the meat to naturally tenderize and it allows the juices to redistribute. If you cut a steak as soon as it cooks, all of the juices will end up your cutting board and your steak will be dry and tough.