1) Flagstick width completely around the hole. ( To be exact, 15 feet radius around the hole)
2) The cup should not be placed on a slope. ( No greater than a 3% percent slope)
3) On any given green there should be at least 14 pinable positions. ( The reason for this is so the injured turf around the cup has time to heal, and it takes about two weeks to heal.)
Overall it is depends on the type of course one is at(private, resort, championship, public, city, etc.), course design(if the course was designed properly, these guidlines will work. If not that means the green complex is a out of control undulating blob), type of players, during the week or on the weekend, tournament(scramble, club championship, high school, professional, etc.)