Wow now theres a subject that cant be answered in a word ,a good bait on one water is not going to be good on all waters ,what kind of water you fishing eg lake river ,high in natural food source clay pit sand or gravel or deep silt choked with weed or clear ,generally you need to do some background checks ,talk to anglers find out whats been used in the past baits used to success in the past an forgot about usually will produce fish ,carp anglers can be a secretive bunch but be pattient someone will talk to you good luck !