It is easy to forget exactly what a credit card is, but essentially the Bank allows you to borrow money up to a certain limit to make the purchases you desire then depending on the type of credit card you may be charged interest for the privilege.
The key is to avoid being charged any interest by taking advantage of the ‘interest-free period’ from your bank. Your bank will be able to provide full details about the interest-free period on credit cards but essentially if you make purchases on your credit card and you pay the balance of the credit card in full by the due date you will not be charged interest on any of the purchases (consult your bank for further advice on individual products).
What this means is that you use the banks money (your credit card) to pay for all your expenses for the month instead of using your own money. In the meantime put your money for living expenses aside for the month into an interest bearing account where you earn interest on your money, or alternatively into a mortgage offset account where you save on loan interest charges. After the end of the month when it comes time to pay off the credit card you then have the money waiting in your savings account, earning you interest.
Stop paying the bank money, and start getting them to pay you!