A writer should hyphenate a compound modifier that comes before the noun it modifies.
Take a look at this example:
No one likes a <em>two-faced </em>person.
As you can see, the modifier <em>two-faced </em>is hyphenated, first of all because it is compound (meaning that it has more than one word), and second of all because it comes before the noun <em>person </em>which it modifies.
Each of us is responsible for our own independence and lives
