Labels are what differentiate a mineral collection from a bunch of rocks. Creating your own labels is important, but so is saving the labels that your minerals came with. A good label should provide a minimum of two things, the species and the locality of the specimen.
The species of a specimen can be identified by an individual with significant experience and knowledge, or by scientific analysis. However, a label makes it a lot easier for those without access to those resources. Therefore, it is very important that the label be as accurate as possible. A label that identifies a specimen as tourmaline is next to useless. There are 35 different species in the tourmaline group, and some of those species have their own varieties. Specificity is a must to ensure accuracy.
Locality is the other part of a good label, and even more important than the species identification. This is because it is much more difficult to determine locality with scientific means than it is species. In addition, locality is one of the more important considerations in determining the value of a specimen. Labels are usually the only thing that can distinguish a mineral from a locality where it is commonly found (and therefore less valuable) from the same mineral from a locality where it is extremely rare (and therefore more valuable).
Again, specificity is important. There are over 62,000 localities for quartz in the world, so knowing that your specimen comes from Petersen Mountain Quartz Mines, Petersen Mountain, Hallelujah Junction area, Washoe County, Nevada, USA, makes that specimen far more unique than some random quartz crystal.
So the next time you are at a show, know that the label is for more than just selling you the mineral specimen. It is written proof of the uniqueness of your mineral, and it can give you clues as to its value. So find a way to keep the labels, whether attached to the specimen or in a separate label catalog; find a way to keep this important record with the mineral specimen.