How are you going to pay credit card bill, if you are running out of cash at the end of the month ?
If you don't settle your credit card bill fully every month, interest rate which seems small since only monthly rate is shown, is actually very high if you compare annual rates. So good policy to pay credit card bill fully every month on time.
Note that the interest free credit period is from a particular date, and not for each purchase. Some people forget this.
And like some people, if you are thinking of saving on the interest free credit period by having your money in the bank and generating interest, do the math first and calculate and see.
Also consider the anual fees and other small small fees, card issue, renewal fess blah blah.
Some shops charge extra % if you pay by credit card to cover the bank charge from the merchant for each transaction.
There are discounts given for cards at various places with lot of conditions.
Check if the discounted products or services are actually what you usually want. There are people who spend thousands unnecessarily to save a hundred rupees
Be aware of credit card frauds and use only with caution at reputed places. Also get an sms alert facility. Not 100% perfect but useful.
Use internet banking and regularly check your purchases and see of you actually made them.
Using credit cards for internet payments can be very risky.
I think new budget removed the 1% or what ever tax on credit card bills. Not sure. If it is still there, depending on your average monthly bill, easier to use a debit card.
But if you *have* the pay back capacity, and know what you are doing

, a credit card is a convenient way to pay without using cash or until office pay day which is usually end of month etc and useful in unexpected large payments like hospital bills (provided your credit limit you get for the card is high).