These are the things that help me sear, and they are not the "only" way. Just what works for me.
So, after removing the meat from the Sous Vide ( save the juices from a big or multiple steaks*)
1. Dry the meat well. After marinading, or applying rub - put the meat in the fridge, preferably on a wire rack for overnite. The cold dry air will help evaporate near surface moisture.
2. Remove meat from fridge, and use paper towels to dab/pat meat dry. Then use PAM or similar spray canola to apply a THIN amount of oil. Then coarse kosher salt sprinkled, and rubbed into surface of meat.
3. Place cold, dry, cast iron or carbon steel skillet in oven, under broiler at 500F for 15-20 minutes. Once the pan is hot - remove and place over largest eye on the range top - on high.
4. Place meat in pan for sear. How long to leave it on each side is dependent on how well done you like the exterior. Sometimes I use a Le Creuset ribbed pan - and sometimes I use a plain surface pan. Aesthetically, I like the look of grill marks. And, the caramelization ( see
https://en.wikipedia.org/wiki/Maillard_reaction ) that occurs adds some flavor in those marks.
But - if you want that nice browning to be more evenly distributed all over the surface ( and more of that flavoring too ) the flat bottom pan will do that.
If you want to focus the finish of your steak on some nice grill marks - pick the ribbed pan. Again, I use both - for variety.
* Now...about those juices that you saved: Pour them into a small stew pot. Add a little beef broth, some ground horseradish, and some A-1 steak sauce, and a splash of white wine if you like... Taste and adjust the ratios to suit you. You can add grilled minced onion, and or canned sliced mushrooms to this as you like too... Simmer for a few minutes...then put them in your gravy boat - and use as a steak topper.