If you write your bills out and mail them, then you should pay your bills at least twice a month to make sure you are paying within the 25-day grace period most creditors offer. Make sure you use the preprinted envelope provided by the company and include the payment coupon to ensure that the payment gets credited to the right account.
It's a good idea to include the last four digits of your account number on the memo line of your check in case the coupon and check get separated. But only include the last four digits in case your mail gets lost or stolen. That will prevent someone from stealing your account information. Make sure you put the proper amount of postage on the envelope, and don't carry your bills around in you pocketbook or leave them in your car for days on end once they are made out. Get them into the mail ASAP.