IMO the VERY best gun safe accessory is a few more guns.
gyrfalcon wrote:silicon socks, rod dehumidifiers.
+1 gunsocks keep things from getting nicked and banged up, they don't take up much space (much less than a soft case). I put rifles in the socks backwards (butt first) so that the loose ends hang from the top, and don't lay on the floor. A garage sale tag on the drawstring helps ID what's inside.
Anybody keep a flashlight in there? Power outages happen.
Spare batteries for the electronic lock? Store 'em in the safe.
Override key if the electronic lock fails? Keep it safe, but don't keep it in that safe...
Ice cream bucket of moms Chex mix-- Lock that up, if you leave it out, it will disappear.
A fight for liberty somewhere, is a fight for liberty everywhere.