At least once a year I perform a full inventory of all my guns, ammo and accessories.
The inventory is for insurance purposes and is done in two ways. I photograph each firearm and I include metadata like Serial Number, Make, Model, Caliber, Accessories and estimated value. This all gets put into a speadsheet as well.
I also include an ammo inventory. This includes Caliber and Counts. It's more important than ever because the replacement value of my ammo is way up. It also keeps an eye on the low water marks for my primary ammo cals.
The accessory list is very important these days as well. I stopped buying cheap scopes for instance. I might add knives to my inventory this year as well.
All this is printed and placed in my safety deposit box.
--A house fire would be a nightmare in any case. But a full inventory can allow you to wake up sooner!