I save all the lids from my lipstick. They can be used for a lot of things, but my favorite one is as a thimble. They are great for pushing pins and things through fabric when it's on your finger.
Do you find the needle slip on the rounded cap? I love the idea but I think I will use a square cap. I once made a thimble out of a 2" piece of leather and duct tape that fit perfectly. This is a great idea thanks for sharing!