When I was in Northern Ghana I watched kuli-kuli being made (and helped a very little--the women laughed at how weak my hands were when I tried to squeeze the peanut [groundnut] paste into balls) it seemed pretty straightforward. That's like saying pounding fufu correctly is easy. Not true.
masoro, salt, powdered peanuts specially prepared (that's the kuli-kuli I've been trying to master), and various other spices: some call for mace, or cloves, maggi cubes, garlic, and in Ghana people commonly mix toasted corn flour into the mixture as well. One of the best kebabs (called chichinga or tsitsinga) I had in Ghana was made from tender beef (often chichinga is made from very tough meats and quite chewy and overcooked to Western palates), and the vendor (from the North) told me he made his own tankora powder that included: white pepper, sweet green dried pepper powder (the only time I've ever heard of that in tankora or yaji powder), dried powdered ginger, ground nutmeg, Maggi and Royco shrimp seasoning cubes, salt, kulikuli, and dried red pepper.