I suspect many folks reading this have sizable gaming collections. (At the very least, I like to imagine we're not alone in having a home full of game-laden bookshelves.) If this describes you, then, here's a tip: Every year or so, photograph your collection. This doesn't need to be extensive; simple (clear) snapshots of what's on your shelves should be good enough and should only take a few minutes, depending on how spread out across the house or accessible your goodies are.
Modern phones have good-enough cameras (and enough storage space) to take decent photos of complete shelves so that individual titles are quite readable if you zoom in.
Taking such photos serves a few purposes:
• First, having the photos on your phone is convenient if you come across a game at a Friendly Local Game Shop that looks interesting. "Did I buy this already?" you might wonder. If the item's on the store shelves and you can see its spine, then you should be able to check for the same spine in your own collection. (Similarly, I've had situations where a friend has asked, "Do you have [Game X]?" And I'll stare blankly at them until I remember my photos . . .)
• Second, it can tell you if you have the base game of an item you're considering. "Oh, Munchkin Apocalypse: Kaiju looks adorable; do I own the core game?" It's easy to know if it's on your shelf if you bring your shelf with you!
• Finally, if there's ever an incident of damage in your home and you have insurance, it's much easier to establish what you have and what needs replacing with such evidence.
Obviously, you could do a much more thorough and in-depth inventorying of a collection if you wanted to. However, as I've gotten older, I find being too obsessive about cataloging gets in the way of my gaming time. But photos? I can take photos while I'm waiting for leftovers to reheat.
-- Steven Marsh