Here is a piece of advice that never occurred to me before the whole job-application mess this year:
If you are a visiting professor or instructor, and you are applying to academic jobs, and most especially if your present employer is hiring, make sure to call up all the department chairs/ heads of search committees and tell them how interested you are in their jobs (and why). Because otherwise they might assume that your own employer will surely hire you (even though this is the dumbest assumption ever - maybe you don't want to work there any more! maybe they need someone with a slightly different specialty! maybe you're doing a great job professionally but there is 'personality conflict' and nobody wants you to stay! maybe their search will be un-approved by the dean despite being approved in advance and they'll not hire anyone after all!* maybe WHATEVER!) and not even bother to interview you.
(My advice in general about visiting jobs is DON'T DO IT!!!! RUN AWAY!!! but obviously it worked out for my spouse - though nobody hires their VAP to a TT job - and your mileage will surely vary. And sometimes it probably is a good idea. The uncertainty made me batshit, though, in case you couldn't tell.)
*This happened to someone in my grad lab. He got an offer letter pending approval from the dean, and then he got a letter from the dean saying "Just kidding! No dice!" He had to go back on the job market the next year. It sucked.