I have been preparing for job loss for a long time now. Here are some things that I have done that have really paid off for me. Not only do they prepare you for job loss, but for advancement as well!
1-Put a little money away every week with the goal of having 6 months in reserve.
2-Take on varied responsibility with your current employer. Do as many different jobs as possible so that you have a cross functional background.
3-Keep your resume current at all times.
4-Take a college class every once in a while for self development, your employer may pay for it.
5-Pay close attention to the industry that you are in and the current trends. Project out what will happen in the next 6-12 months.
6-Network, network, network! Maintain relationships with friends that have moved on to other companies.
7-Don't burn any bridges no matter how badly you may want to!
8-Stay one step ahead of your company and look for a new job before things get too bad.
9-Be open to relocation for the right opportunity.
10-Stay upbeat and positive no matter how bad things get. Keep that "survival mind set"