Methods of Choosing Your Destiny That Have Not Been Used by Ya Novels (Yet)

i was sitting in class thinking about how in the book the city of ember (remember that book?) they were like assigned careers at random by like drawing names or something? and then i thought of all this other stuff
  1. length of your arms
  2. how many pushups you can do
  3. you wake up one morning in the clothes of that profession
  4. whether or not you can roll your Rs
  5. you put on nail polish that is like mood nail polish except it changes color to tell you your destiny
  6. your wisdom teeth tell you (because they are very wise)