Your job can evaporate or the business you work for can vanish, for reasons that are neither predictable, your fault, nor even the business owner's fault. It happens all the time. To think otherwise is simply self-delusion. Factory workers face layoffs, businesses face cutbacks due to a drop in revenue, factory operations get sent overseas. It goes on and on.
Think about it. What would you do if you were suddenly told "don't come in tomorrow"? How long would your pocket cash and savings hold out while you search for another job? Would you be like one of those poor slobs who winds up living in his car and from hand-to-mouth, helped along by soup kitchens and government handouts?
How far are you from that point if you lost your job today?
There are a number of options people advise you to consider. One of the best is, of course, developing multiple streams of income. If I lost my job, I know I'd be suddenly filing a lot more stories with Associated Content and hunting up and listing more stuff on my eBay store.
WHAT IS IT?
For the past several years, I have been assembling a Go to Hell Book. It contains plans, notes, and clippings on what to do if everything "goes to hell."
I remember it all started when I printed out an article online on services the author began offering when she expanded into freelance writer on a fuller basis. It occurred to me that even though some of this didn't appeal to me right now, if I was in a situation where I lost my job, I might find myself free to expand. It wouldn't hurt to have the how-to information at hand as well as some memory-prodders and idea-starters.
I had one situation where my job disappeared within a matter of minutes and, despite reasonably generous separation pay, I was on my own.
Obviously, your first thought is how long you can stretch your resources last, then, how to replace that income.
In my line, radio broadcast jobs require ranging geographically far afield as a rule. There just aren't that many radio stations. That implies you'll be moving, even if you've put down firm roots where you are at. Personally, I also face what has become an increasingly large issue as the years pass, my employability due to age (now 58).
So, when I cam across that article on online services, I put it in a document protector and stuck that in a looseleaf filler notebook that came to be called my Go to Hell Book for when everything falls apart. I've been keeping my eyes open for input ever since. Anything that looks like a solid lead on something that I would seriously consider if I find myself on my own gets torn out or copied and goes straight into my Go to Hell book.
CUSTOMIZED FOR CONVENIENCE
Everyone has his or her own needs. This Go to Hell Book is certainly adaptable to those needs. You could use the book to keep an updated hardcopy of your latest resume, which you need to keep at hand at all times anyway. You may want to post job search ideas, contacts, that sort of thing.
My Go to Hell book is a level above the other reference collections I've put together in notebooks. I expect it to expand as time passes and I uncover other items.
Let's make a distinction here. This is not material about things I'm already working on like writing for AC, selling on eBay, that sort of thing. These income producers, a lot of fun, but they won't sustain me, probably not even if I increase efforts. Instead, the reference material in my book focuses on fallback ideas, hot prospects that I can dive into when my calendar suddenly opens up and leaves me adrift. And from time to time I'll review the Go to Hell book just to see if there's something there I feel I can tackle now rather than later.
THE PLAN
My basic plan is simple. If I lose my job, I immediately increase efforts at producing stories for AC, max out the number of salable items I can list on my eBay store (The Book Nutz, thank you for asking), and I start examining my Go to Hell book for money-producing ideas that I can begin expanding my efforts into.
Hopefully, I'll never have to use that book, but if I need it, it is there.

