The idea with the initial sear is to build as much crust as possible. However, you only want to cook it to the first temperature down from what you're aiming for and take it off the grill/out of the pan to let it rest on a wire rack. Let the steak cool down completely, which is the most important part as it helps retain all the juices of the steak. The reason steaks often lose their texture and the impact of the flavour is dulled is because they don't rest between sears and when you cut into them you end up with that steak juice puddle on your plate. That's no bueno. The last part after cooling is to crank the heat to maximum and go for a final sear, this is to bring the steak to the desired temperature, so it's actually the fastest part of the cook. Depending on how thick cut the steak is, this often ranges from 60 seconds per side to 2.5 minutes per side.
When you slice into your steak, you won't have any juices escaping, you'll have a gorgeous crust to counter balance the texture and your temperature will be right on the money while the steak retains all of the heat.
I like thick-cut dry aged ribeyes. The final sear is where I baste with a mixture of dry aged beef fat, thyme and garlic that's been rendered over the heat. If you baste in the first part, you risk "boiling" your steak rather than searing/grilling.