IMPORTANT: If you borrow money from someone pay it back as soon as possible. In full. If you borrow an item, return it in excellent condition. I’d say if you borrow a car, return it with a full tank of gas but hopefully by the time you’re driving there won’t be any combustible engines. So return it fully charged!
Start “home economics” school with them. Laundry, cleaning, cooking, how to change a diaper, comfort a baby, soothe a toddler, what's involved in caring for pets, budgeting for food, keeping track of maintenance schedules for humans, pets, cars and machines. Engage with guests, be a good host, etc. Know when and how to tell someone to GTFO of the house (racist or misogynistic speech, etc.) Every kid needs to learn the art and science of home management. Look for and point out examples in books and movies of good home science skills.
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
Beware that when you’re first exposed to a new thing: a car, a college tour, house, etc. you will feel AMAZING and totally seduced by the shiny newness. Be cool. Remember that glitters is not gold. Things don’t need to be perfect and even if the house is it doesn’t mean life will be.
Check out the Jesuit Volunteer Corp. A short but deeply meaningful immersion into service, faith in action, selflessness and living on a lot less than you think you need.
It’s fine, great, to be thrifty. But please don’t be cheap. Hard-earned money should neither be squandered or hoarded. Enjoy your success! But save more than you’re comfortable with. It’s like my running coach used to say: Keep going until you feel like you’re gonna poop your pants, then push yourself to do another mile. Point is, it should hurt a little.
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.
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.