Strange as it may seem, one of my favorite home storage tools is my permanent-ink marker. I actually leave one on the shelf in my storage area.
I am constantly labeling and relabeling cans and buckets to indicate their contents and volume. I use packing tape, which I fold over on one side (to aid removal) on each bucket and write the contents on the tape with my handy marker. I also label all of my storage products as I stock the shelves both with the purchase date as well as the expiration when I can see/find it.
Last week, I stocked up on some olive oil, shortening and canola oil for my storage. I had to squint to see the recommended expiration dates on the bottles, so I rewrote those dates on the bottles with my marker. Doing this makes it much easier to pick the bottle with the closest expiration date, especially when I'm in a hurry.
You can get permanent-ink markers in many different colors. If you were really ambitious, you could color code purchase and expiration dates. You could also color code products based on contents. Click here for a previous post with more ideas for labeling home storage.