The next skills would be as follow:
Astrometric Pinpointing to lvl 2.
Astometric Rangefinding lvl3
Astrometric Acquisition lvl 2
Astrometric Pinpointing to lvl 3.
Once it done, drones skills will be next priority.
I prefer train this skills even I am comfortable now simply because less scanning process takes, more ISK can be earned. It is quiet obvious of course.
It took more than an hour to figure out which signatures worth our time, scan them to 100% and bookmark.