I put in the slow cooker, put the lid on and switch it on. Don't add anything at all. But when I do it, it's to strip all the meat off the bones easily to use in curry/enchiladas/etc, not to eat 'as is' - it can be a bit bland on its own.
No, you don't get lovely crispy skin, but you do get every single scrap of meat off the bones, and it's nice and tender. If I buy an expensive free-range chicken, I do like to know I've eaten all of it that I could!