ALWAYS ASSUME YOU ARE FIRED
Even when you have a job or are working a client. Run Scared but be pro-active. Keep your resume out there, keep networking (most important) and pile up reserve cash. Keep your lines of communication alive, send out newsletters, etc. But always act as if you actually ARE fired and that makes finding the new job all the faster.
On interviews - I never let a company interview me. On the contrary, I AM INTERVIEWING THEIR COMPANY to see if they are GOOD ENOUGH for my standards. Turns the whole argument around and puts me in a position of strength and power.