Technical hiring managers need to take their requisitions a LOT more seriously than they have, over the last half dozen years.  Too many requisitions are vague, incomplete and obviously very political. They are too general for a candidate to prepare him/herself for a series of interviews. 

A hiring manager should spend the time to actually define goals for a new project, identify and define the tasks comprising that project, and then look at each and every skill that a task requires, and finally estimate the mentoring necessary to provide to a new hire. Don't hire somebody if you don't have time to brief them on the project.

Every job req should be defined at a professional level. No job should ever be defined as a tryout, temporary or support job where you will just fire someone who isn't working out for some vague reason.  Vague reasons burn up time and cost money.  don't even do this if other hiring managers are doing this. If your company has a policy of hiring this way; start looking for another job yourself.  You are better off hiring a good person for more money and training them, than you are burning up a year spinning through five eager and inexpensive new hires who don't work out.

After looking closely at a new project, the hiring manager should write specific, carefully considered requisitions for the jobs required -- AND spend a little time networking publicly to see if he/she can locate candidates himself.  Being public is important -- just calling up a few friends isn't enough, and sometimes is not even appropriate. 

This basic stuff is NOT what most hiring managers do.

Candidates need to use unemployment time to brush up on the business-oriented skills that impact their professional role.Take a professional course if it's appropriate. Zero in as you can, on your specialties and strengths. 

Isolation is your enemy.  Learn to network, and learn something about starting an appropriate business for yourself. LinkedIn is mandatory now, but not sufficient -- you have to find a way to get in front of a real person every day.  Also keep in touch with employment agencies and jobs boards; just don't expect them to be reliable and honest, or to produce a job.  YOU know more about your job field than THEY do.  ... and don't apply for everything you see. Treat senior recruiters with respect -- they can be helpful sometimes. You might run into them at professional or business meetings. They aren't the ones who cold-Call or send email.

Nobody knows enough about any of this to call themselves an expert. Neither do I.  Whether you are hiring, looking, or representing:  Good Luck.