I am just quick making another post because there are also a few other things that I forgot to mention. It is a good idea to field test your gear for several good reasons.
1. It is good practice. Get comfortable actually using it, even if it is for mundane things. Good example is what I mentioned in my last post, I made my lunch with it. What good is your gear if you do not know how to use it or how it works? Testing in relatively safe conditions before you happen to get into trouble helps.
2. It shows where you can make improvements with your bag, and your personal skills. Are there things that you forgot to add? Or is there something that you did not think of, but found you could use later? For example, my bag could use a rag for cleaning things like dishes. Or maybe an extra pair of socks to keep your feet dry? If you do not have it, then you cant use it.
3. Testing shows how well your gear performs too. Maybe you bought or made something that was supposed to work, but didn't?
4. It gives you a chance to use up the perishable things in your bag so that way what you have does not go to waste. Waste not, want not.
These are all good things to keep in mind when you put together an emergency bag. Someday you may have to rely on it.