well, how detailed do you want to be?
make a list of items you want to keep on hand and the corresponding 'restock' amount. next to that, a blank where you can write in the amount you actually have. next to that, a tally box.
tomato paste (2) ____ ____
pasta (3) ____ ____
put this in a page protector and tape to the inside of the cabinate/pantry door. keep a fine tipped dry erase marker in there too.
inventory your pantry, and enter the quantity on hand in the first blank. every time you use an item, tally it up in the second blank.
tomato paste (2) _5__ |||
pasta (3) _6__ |||
you should be able to tell at a glance when you need to restock an item (like tomato paste in the example). once you replenish, wipe the dry erase notes off for that item and correct them (hence keeping the list in the page protector).