cut all the little things that you can. that helps. buy quality ONCE for the essentials. If you have to spoil the kids, trick them into wanting things like desks, laptops, ipads, etc... things that'll last 10 years and you can always use. Plastic lego sets don't usually appreciate in value lol.
oh, and make more money. solves most problems. Get good, then get better. never stop studying.