Most people have no idea how to balance their finances.
It's common knowledge in the personal finance blogosphere that everyone should save a MINIMUM of 20% of your income.
The most common excuse is that you don't have any extra money right now. While this may be true for some select individuals in select geographical areas, for the majority of people this is not the case.
A well known metric for finance is called the balanced money formula.
50% of your income on needs: rent, food, transportation, etc.
30% of your income on wants: eating out, entertainment, etc.
20% of your income on savings: retirement accounts, emergency fund, paying off debt, etc.
This allows you to still enjoy the money that you make, but still save a mostly adequate amount. For people in debt it is often advised to redirect a percentage of your wants category into savings.
The most important part of financial freedom is to keep your needs below 50% of your income. This has a nice side effect where if you live in a dual-income household, you can lose one income (due to health, unemployment, etc.) and ordinarily not go into any debt!
Personally my current income is divided up into: 50% needs, 10% wants, 40% savings.