By knowing your income and expenses, you will be able to see where you can save money and where you can reduce your expenses. List all your regular income, then identify your regular expenses (rent, bills, loan payments, groceries, etc.) and your variable expenses (outings, vacations, etc.).
Track your expenses by noting them as they occur. This will help you better understand where your money is going and spot unnecessary expenses. Applications such as Mint, Fudget, Spendee or even Hardbacon are available and easy to use for this purpose.