To motivate kids, keep it simple and try to find entertaining ways to teach them about money. Show them with games that when they manage their money wisely, they will be able to make their money work. To start them saving, tell your kids to put all the coins less than € 1 in a clear jar instead of a piggy bank so they can see their money growing. Once the jar is full, they can decide freely what to do with the money.
Even making a budget can be funny with a little imagination. Ask them, for example, to find a job (in any newspaper with the corresponding salary) and an apartment or a house. Then they have to note all their expenses needed to live (power, internet, food, furniture, entertainment, etc.) and to calculate the difference between income and expenses.
By following these advices, you will help your children developing good habits for the future. Once they become adults, they will have the best chance of having a healthy relationship with money.