The American Economic Association allows newly minted (or almost minted, in most cases) doctorates to send an explicit signal of extra bonus interest to two of the (usually 100-150) schools / governmental or quasi-governmental institutions / firms to which they have applied.
As I sometimes get emails from students asking about strategy, here it is: send your signals to places that you would like to go to for some reason that would not be observable to them based on your job market packet: e.g., your favorite cousins live nearby, you've always been a Packers fan ever since you first saw the cheese hats, etc. In terms of quality, I would pick places for this purpose that are around your expected placement level.
Here is a deeper, and longer, discussion from Greg Mankiw's blog a couple of years ago.
Who was my favorite student this term?
8 months ago