Have a LinkedIn account and keep it up to date. List the things that do not seem relivent to an employer such as voluntary activities and charitable organisations. This gives an employer a feel of who you are. This may seem to be risky but being generic and forgettable is worse. I have taken the risk of listing this blog in the 'projects' section. An employer will recognise that it was written by someone who wishes to help others and will probably forgive my sometimes eccentric opinions.
Maintain more cash than we think we need in our current accounts. Pretend our next wage slip is our last.
Reduce long term debt such as mortgages and student loans. This may not seem a good idea in a world of low interest rates but it will seem much wiser when disaster hits.
Check our Facebook accounts. There is a tendency to behave on Facebook as if one were among friends. It is a little like the office party where one becomes drunk and makes a pass at the personell manager. Read ones entries and delete them as needed. Check privacy settings. Exactly how much is one sharing? No nude pictures! Even with a password!! Ever!!!
Have food in the house. This is good advice for many kinds of crisis. The food should be cheap and fairly compact. My own supplies consist of various beans and varieties of rice. This combination would be of little use if I were denied heat or water but is an excellent way to stay healthy with little money if I should lose my job.