Start to keep your personal finances in order. Open every bill or invoice the day it arrives. Put the bill back in the envelope, write down the date by which you have to send the check, and put it in a pile with the other bills, arranged chronologically.
Designate a specific time each week or month for paying the bills. You might want to do it once a week, once every two weeks, or once a month. But make sure you do it by the time you decide upon.
Some people like to wait until the very last day before paying a bill; others like to pay as soon as the bill arrives. Either way is fine, but strive for consistency.
Your personal finances can be a source of real pleasure in your life — orderly, organized, accurate, timely. If you are a little short one month, call your creditors, explain your situation, and indicate when and how much you intend to pay back each month. You'll be surprised at how willing most people are to give you slack if you only ask.— Alan Epstein in How to Be Happier Day by Day