Do you have extra negatives lying around from your photo processing days that are not in any kind of order or that you just don't save?
How about putting them to good use on your scrapbook pages or card-making projects?
Use the negatives film strip included in your stash of developed pictures as pockets for your pages by adhering it to your cardstock or patterned paper on the sides & bottom only. That way you will leave the top open to insert extra photos, journaling tags,ephemera and more. This will increase the amount of "crafting real estate" on your pages & projects by serving as a pocket.
You can cut them up and use them as frames for small photos or place rub-ons directly on them. You can use them as windows or step ladder simulations on your projects. They can serve as transparencies too. Those are just a few of my ideas to help jump start your creative juices.
The possibilities with this are only limited by your imagination.
So go ahead & give it a try.