"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.
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
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.
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.
There are things you should not say:
Never comment or ask a woman about her age or weight.
Never comment on how many kids someone has (or doesn’t have.) The size, timing, composition, etc of someone else’s family is not your business to weigh in on. You never know who is struggling with loss or infertility, etc. And if someone announces they are expecting their seventh kid, the only correct response is “Congratulations” “How are you feeling?” etc. Just like you would if it was their first. Never ask someone how much weight they lost. If they’ve lost weight, just say “You look wonderful/amazing/ fantastic, etc.” And of course never comment on anyone having gained weight. Just say “You look wonderful.” And never never never ask someone how much money they earn or how much money they have, or how much they owe or paid for something, etc. People’s finances are personal, and are just not any of your business.
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!