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.
Start a yearly “review” right before school year. Raise allowance as appropriate. If they want more money, they’ll have to take on more responsibilities.
Set up automatic payments so they are initiated on your end, so that you send out money to the bill/ company you’re paying instead of giving them access to take money out of your account.
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.
Check out from the library or Amazon: “My First Money Book: A Guide for Parents and Children to Saving, Spending, Sharing, and Investing Your Money” by Reggie Nelson
Work on developing a “no shortcuts” mode. Looking for a faster/easier/bare-minimum option isn’t always bad. People get paid a lot of money for creating efficacy. But there are times when that approach is wrong. Anything you want to grow from (relationships, school, work, wealth, health, knowledge, etc.) those things deserve your full effort, focus and dedication. Play. Definitely play! But don’t f*ck around.
"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.
Have a yearly “review” right before school year. Raise allowance as appropriate. If they want more money, they’ll have to take on more responsibilities.