Possible universal themes to get you started
abuse of power
action vs apathy
beating the odds
beauty
coming of age
corruption
courage
effects of the past
faith
fall from grace
family
fate
fear
fear of failure
freedom
friendship
greed
hate
heritage
heroes
honesty
innocence
justice
love
loyalty
manipulation
mothering
nature
need for change
obligation
parent-child relationships
peace
peer pressure
perseverance
Power of the mind vs
authority
prejudice
price of progress
pride
quest for knowledge
religion
revenge
secrecy
security/safety
seizing the moment
survival
the overlooked
the road not taken
war
winners and losers