Rub with Pappy's seasoning, add a little parsley, pepper and either garlic powder or minced garlic, add just a little beef broth or water to crock pot. You can also brown up some onions and unpeeled carrots and quartered potatoes in another pan in hot olive oil - deglaze with the beef broth and add all that to your crock pot.
Honestly I usually just rub with Santa Maria or Pappy's and roast in the oven for 425 for 30-35 minutes. [meat temp 135 for medium rare and 150 for medium] Tent with foil after roasting for 10 minutes or so before carving.