If using cash, at the end of the day, empty your wallet. See any five-dollar bills? Nab ’em and put ’em in an envelope. Do this every day, and at the end of the month, deposit the bills into a savings account. You’ll be putting money you would have spent on other things into savings, and you’ll trick your brain into making it part of your daily routine. You’d be surprised how quickly it all adds up.