Baby boomers most of your expenses go where?

Hello Baby boomer what do you spend money mostly on for your young kids?
I spend much on buying diapers as there are no cheaper alternatives till they are well potty trained.ButI always buy them in bulk as they cut the costs as much as 20%.Others are clothes which are better bought during sales as they equally reduce the cost.
let me hear from you on these areas and what to do to save costs.