So I wanted to check whether I should add money to my account just for the visa
No, no, no! More below. It's called funds parking. Read this excellent answer as well.
Also will credit card statements help?
Yes, if they show a healthy repayment history.
A visa officer typically have an extremely short time at best measured in minutes (and you probably won't need two hands to count the minutes) to decide. S/he will be provided with all the evidence and s/he needs to construct a story of your life and decide whether that story leads to an illegal stay and work in the country you are visiting or a return to your home. Proving you have the funds for the trip is of course crucial because the lack of that will lead to immediate refusal. If you had kept your money in the bank account every month, it'll be easy to see. It's still possible but make sure it can't be construed as a rich uncle borrowing you money for a short period of time.
Beyond that comes the "let's try to divine whether they will return" part and they simply go by experience. People with a steady job (proven by the monthly deposits) and a healthy credit history are very likely to have a steady life they will want to return to. If your monthly income is (far) above the unskilled laborers' then it's very unlikely you could find such a well paying job in the country you are visiting when you are working without the necessary permits. This is what they want to see. Don't ruin it by a sudden deposit.