If your slow cooker has a ‘sear’ setting on it you can brown your meat directly in your slow cooker and skip the extra skillet. This would make your slow cooker beef tips a true one-pot meal.  You can skip the step on searing your beef cubes however, I highly suggest that you do not. By searing/browning the beef cubes, you are locking in the juices and creating a great texture and color to your beef tips that does not happen if you simply add the raw beef to the slow-cooker.