I am right there with you on cast iron. For me, if a steak is good enough, it needs nothing but olive oil and salt. I let the steaks come to temp, coat them in quality olive oil, salt my cutting board and drag the steaks heavy handed through the salt to cut it into the meat. They sit while I dry heat the cast iron till it's as hot as can be. Sear 3 minutes a side and finish at 350 dependent on the thickness. I like mine a true medium rare but pink rare is also acceptable. Blue rare I can eat but I don't like nearly as much.
Here is one prep I use that isn't so minimalist. Get a small tub of blue cheese crumbles, a stick of butter and sweet basil. Melt the blue cheese into the butter and basil until all the smallest pieces have dissolved, pour it into a square Tupperware and throw it in the fridge for a few hours. Get a jar of malt vinegar pickled onions and pour the vinegar into a glass or ceramic baking dish and marinate the steaks 20 minutes per side and drain the vinegar into a sauce pan (this is a no no most times but with quality beef, I am not concerned). Salt, oil and pepper the steaks. Add 1 cup brown sugar and 1 tbsp Worcestershire to the vinegar and start reducing. Once that is going, I seer the steaks for 3 minutes a side and grill the pickled onions. Then the steaks go into the oven for 8-12 minutes depending on the thickness. Keep an eye on the sauce and pull the butter out of the fridge. Smack it out and you should have a square with butter on the bottom and blue cheese on top. Fourth this and when the steaks have 1 minutes left in the oven, add one butter cheese cube to the top of each steak and turn the broiler on. Pull the steaks which will now have a nice coating of blue cheese and butter and plate on some parsnip puree with grilled pickled onions on the side and drizzle with the malt vinegar, brown sugar sauce.