You might want to do some comparative mythology, to check out what different mythologies have in common, and how they differ. Perhaps the first comparative mythologist in history was a certain Xenophanes, who pointed out about 2500 years ago that people make gods in their likeness, black people like black people and northern Europeans like northern Europeans, and that horses and cows and lions would do the same if they could.
For hero mythology, you may want to check out Lord Raglan's Mythic-Hero profile. Most legendary heroes depart in some way or another from this profile, so consider it an average profile:
- The hero's mother is a royal virgin, while
- his father is a king, and
- the father is related to the mother.
- The hero's conception is unusual or miraculous; hence
- he is reputed to be a son of a god.
- Evil forces attempt to kill the infant or boy hero, but
- he is spirited away to safety and
- reared by foster parents in a foreign land. Besides this,
- we learn no details of his childhood until
- he journeys to his future kingdom, where
- he triumphs over the reigning king and
- marries a princess, often his predecessor's daughter, and
- becomes king himself.
- For a while he reigns uneventfully,
- promulgating laws. But
- he later loses favor with his subjects or with the gods and
- is driven from the throne and the city and
- meets with a mysterious death,
- often atop a hill.
- If he has children, they do not succeed him.
- His body is not buried, yet
- he has one or more holy sepulchers.
As to creation myths, Scott Leonard's book
Myths and Religion has some classifications of myth motifs that various authors have proposed. The one I like the best is Marta Weigle's; she builds on work by Mircea Eliade, Charles H. Long, etc. in
Creation and Procreation: Feminist Reflections on Mythologies of Cosmogony and Parturition, she proposes:
- Primordial elements meet or mingle or otherwise get disturbed.
- A god creates by secreting something, like sweat or blood or semen or a parthenogenetic child or a spun web or excretions.
- A god either sacrifices him/herself or gets sacrificed to form the raw materials for creation.
- The hatching of a cosmic egg or dividing a closely-embraced earth and sky.
- Someone dives into the primordial ocean to get some sand or mud to create land with.
- The first people emerge from a small, cramped world into our larger world.
- There are two creators who either cooperate or compete.
- Deus faber is the "divine maker"; where a god forms something out of some material.
- Ex nihilo is "out of nothing", often creation by a god's command.
Some of these motifs should be easy to recognize in Biblical, Greek, Norse, or whatever other creation myths you might be familiar with.
Turning from structure to function, you may want to consider what myths "do"; here are some functions:
Etiological myths or Just So Stories: these explain how something came to be. "Just So Stories" is the title of Rudyard Kipling's was inspired by such myths; there are some much myths in the Bible like the Adam and Eve story for why snakes crawl on their bellies and the Tower of Babel story for why people speak different languages.
Charter myths: these justify some practice or institution of whatever. In the six-day creation story of the Bible, God rests on the day after his labors, celebrating the first seventh-day Sabbath in the history of the Universe.
Related to that is legendary founders and lawgivers and inventors like Moses, Romulus (Rome), Lycurgus (Sparta), Theseus (Athens), Perseus (Mycenae), Minos (Crete), Cadmus (brought the Phoenician alphabet to Greece), Daedalus, etc. Lawgivers often claim to get their laws from gods, and inventions are sometimes attributed to gods, like Prometheus giving fire to humanity.
Finally, some myths seem designed to teach moral lessons, like the story of Daedalus and Icarus, who escaped Crete by constructing wings for themselves and flying. Daedalus flew cautiously, and made it to mainland Greece. However, Icarus dared to fly much higher. As he approached the Sun, the wax in his wings started to soften and his wings fell apart, making him fall to his death. So this story may be interpreted as a warning not to be too reckless.