I have just been listening to an excellent piece of student work. A recording of an acoustic guitar, well played, in a good acoustic, with good microphone technique. What's not to like?
Well in this case what was not to like was right at the end. When the musician played the final chord, as it faded away he either moved or sniffed. It was difficult to tell which, but it spoilt the last moments of the recording.
This is in fact a common thing to happen. There's something in human nature that makes us fidget when not actively engaged in something. So while the musician is playing, all is well. And any movements or nasal occurrences are masked by the sound of the instrument.
But when those final notes are dying away, the fidgeting impulse kicks in.
The solution for this, in the studio, is simple. Explain to the musicians what the problem is, and that you will say “clear”, or whatever, to indicate when the take has ended and fidgeting may begin.
Once you have fidget noises in your recording however, you will find them much more difficult to deal with.
There should be a saying for it. Something like, “A fidget fixed in the studio saves many hours of editing and fading in post-production”. Can anyone put that into a snappier form?