One thing no-one has mentioned is the "sixth sense" that can come with experience.
Dark night, Twin-jet airliner. Light icing conditions. I "sensed" something wasn't quite right. The hairs on the back of my neck were almost standing up. A check of all engine, system and flight instruments showed all was normal, but the sensation would not go away. A check of the wing with the ice-light; all OK, anti-icing working normally. Only a short sector, and at top of descent there was a terrific vibration and the port engine warning for severe vibration lit up. Check list followed, and engine shut down. I was now quite calm and relieved. The unknown I had been waiting for had happened. An engineering check after landing revealed no damage. The engines were rear-mounted, and the only explanation anyone could come up with was that, although the wing leading-edge anti-icing was functioning, somehow a large chunk of ice had built up on the wing surface, and detached itself into the intake.
I was talking with one of the fleet trainers about it a couple of days later, and his comment was that experience can build up a feeling or "sixth sense" of problems, even when they are not detectable by normal means. Dunno, just saying.