I love mason jars.  I have a large collection of them.  Aside from their most obvious use, they are used quite regularly in my kitchen.  They can hold just about anything, but I love using them to store mixes or ingredients.  And I make things really easy on myself concerning their use – I write directions for their use right on the underside of the lid.  I always forget how much popcorn to how many tablespoons of oil for making popcorn on my stove.  I hate having to pull out my huge master cookbook for such a simple recipe.  So, I write the important info on the underside of the lid.  I sometimes use a dry-erase marker or a permanent marker.  If I ever change ingredients, sometimes the permanent marker will scratch off.  If not, I always save my used lids every time I open a jar of home canned food.  I always have old lids around ready to be used.  You can’t reuse them for canning, but you can reuse them a bunch for dry goods.  This also works great on mixes, such as cream-of soup mix or the hamburger helper mix I always keep on hand.