I tend to use the following guidelines for Conan/3.5:
lvl 1: priest out of seminar, apprentice craftsman, warrior out of 'basic'
lvl 2: average priest, craftsman, warrior
lvl 3: head priest of small temple, expert craftsman, veteran warrior/sgt.
lvl 4-6: head priest of large temple, master craftsman, lieutenant/captain
lvl 7-9: generic captain of pirate vessal, generic high priest of city, generic general of army
lvl 10-15: regionally known PC or NPC (great swordsmith, powerful high priest, great swordsman, named (feared?) pirate, general. These NPC's are not generic, they are named/stated INDIVIDUALS.
lvl 16-18: Legendary PC or NPC, one of the best living in his profession, known or heard of throughout the continent.
lvl 19-20: Mythic PC or NPC. The best or one of the best in his profession that ever lived.
When using Castle's &Crusades, I use the following:
1HD human: average person/craftsman/man-at-arms
lvl 1-3: average Cleric, trained Fighter, Knight errant, Wizard just out of school
lvl 4-6: "low level leader level", head priest of individual temple, lieutenant/captain of guard, baron of small fief, experienced Wizard. These people are usully the best in a town.
lvl 7-9: "high level leader level", captain of the guard, high priest of a city, duke/count of large fief. Usually the best in a city/region.
lvl 10-12: Name level. Lord, High Wizard, High Priest of a diety. These people are known throughout the land and are the best of their class in the region/kingdom
lvl 13+: These people may or may not exist. These are legendary warriors, mythic wizards, or clerics of unheard of power from their diety. Those from the past are now the Stuff of Legends. If alive, they are in the top in the world of their class. If evil NPC's, these people threaten whole kingdoms.