Checking and replacing batteries isn't enough -- you must function test all electric and electronic devices. They break, often at inconvenient times.

All tools (including those made with high quality stainless steel) need to be cleaned, lubricated and occasionally have the blades sharpened. Don't leave them out.

I once found that some emergency food bars had been opened and nibbled upon by a rodent. This led me both to replacing the compromised food bars and laying out new traps for the varmints.