When you’re recording your music live, so-called breakdown charts are very helpful. Basically, this chart lists every cue that needs to be recorded with title, length and specific instrumentation of the cue. Also, it notes specials like when there’s a solo violin passage and things like that. In order to keep a quick overview over the instruments needed, it lists all available instruments in a row like Fl, Ob, Cl, Bsn etc. and every row for specific cues the numbers needed for this cue (e.g. 2, -, 2, 1 meaning that 2 flutes, no oboe, 2 clarinets and 1 bassoon are needed in that specific cue).
HERE is an example of such a chart from one of my last film scores.
Often, your copyist service might prepare such a list but if that is not the case, it is still a very good idea to prepare one by yourself. The first advantage is, that you can plan the recording order with this breakdown much better, sending some musicians home early that are not needed for remaining cues. It is also extremely helpful just to make sure you got every cue recorded which might be an issue on larger projects with many cues and it is also very helpful for your recording engineer as he/she will know from this list exactly which microphones are needed and in case of instrumental solos can adjust the mics without needing to ask which will save a lot of time.
Preparing these charts is quite a lot of work but it will save you alot of time during the session and make the session much smoother.