another thing that might help, sometimes I mix my own embossing powders but only do a small quantity. I use these really small,
clear plastic jars (round, about 1" tall/1" diameter). This one has screw-on lids, mine have snap on lids. I purchased them at a teacher supply store (for paints) but they don't have them available anymore. They really are small and would be easy to store. You could have several different colors available and just refill from your storage shed.
And instead of buying little jars, if you have a Sephora near you, they use cosmetic sample jars with screw on lids, maybe they would sell you some. They have a couple of different sizes, so make sure you get the larger one, not the smaller one.
Also, save some of your SU stamp cases, they are great for storing these small items and then you can layer the stamp cases in a clear shoe box along with your basic tools and your heat tool. The stamp cases help to keep everything together. I've unmounted my stamp sets and am using the boxes to store my Twinkling H2O's by color family as well as decorating them and using them for office supply storage.
hth...pam