Rather than giving my daughters a weekly allowance I gave them a "purchase credit". I put up a whiteboard in their room to show their account balance. They could buy something by saving enough credits or they could go into debt (credit). Also added to this for birthdays/Christmas etc. Older daughter showed an interest in saving (she still does as an adult) and younger daughter was usually in debt (she is a saver now). Since it was always visible, it became competitive too. Nothing like saving enough credits to buy something they really wanted.