Start by accepting that the right answer is: there are no right answers. Since every child is different in age, personality, and maturity the right way of handling money is going to differ. What you can do however is try different ways to find out what works best for your own family.
A good starting point for weekly allowance is age x 10 kr. When your child starts to learn to not spend it all at once on the first day, you can try to give out larger amounts on fewer occasions. Money once a month requires more discipline but teaches an important lesson in saving.
Do the child have to “earn” their allowance by doing chores? A tricky question that’s actually really easy, you decide what feels best. Earning an allowance is a good way to show that money is not free. And we are not talking about heavy labor. Tasks such as wiping the table or cleaning their room can be enough.
Children will talk about their allowance with their friends, as should you with other parents. By asking other parents you may get inspiration and ideas of what works and what doesn't. From amounts to pitfalls and tips. But remember, you decide what works best for you – everyone is different and you pay what you think is reasonable.