So little things to remind yourself your trying to be mature. Remind yourself a lot and work hard on it. And before too long you will have picked up those habits as 'a norm' in your life you won't think about it. So set reminders on your phone for any bills that are due like a day before. Then don't put it off and actually go do it. Giving your word and holding true to it is a big sign of maturity.
think before you act. it comes with time and patience.
That sure beats what I was going to put.
Think before you speak