Have them sort change, and eventually to count it. It teaches them to gather things that are alike, it's an introduction to money and it occupies them for 15 minutes! Just make sure they're old enough to be past the point of putting coins in their mouth.
Take the family on periodic “spending fasts.”
As an exercise, go a day, a weekend or a week without spending any money. Make due with what you have.
Encourage participation. Tie in spending fasts with holidays, lent or in support of a cause.
Start saving money early. Save as much as you can.
There are plenty of things worth spending your money on, but be mindful about your money - Don’t p*ss it away.
Be discerning about your sources of information. Some red flags: Too good to be true. Get rich quick. Chosen race. Any race or group blamed for societal problems. Fear of change. Threats of real or metaphysical harm (I.e. $@!#%) or bribes with reward.
Start saving for retirement with your very first paycheck. Put away the MAX, you’ll never miss it. If the company doesn’t offer 401k then we’ll open a Roth IRA.
Practice “going without.” Talk about how nobody gets what they want all the time. We should learn how to just choose to go without something we want. Get them in on the discussion and pick something every day to do without.
"Watch the pennies and the dollars will take care of themselves." - Ben Franklin
This works with money and with other areas: Be faithful in the little things and the bigger things will take care of themselves. For example, if you don't get comfortable with telling little lies then you'll never tell big lies.
Failed?
Lift yourself up, or live there.
You know the work you need to do, be it physical, mental, emotional or spiritual, etc. So do it. Do the work.
The only bitterness in failure comes from not having the guts to get back up again.