Well, for the unorganized (like me), stock up on things when they go on sale and basically always have a back-up. For the organized, keep a list of what you typically use. As you get close to running out of things add them to your shopping list with a "needed right now" "needed soon" or "buy only if on sale". Then buy according to priority until your budget is exhaused. . . . I'm sure the organized on this site will refine the method
