I have started doing airliners only.
Longest in MsFS being around 13 hrs so far.
I’ve joined a VA (virtual airline) as well as IVAO and VATSIM for extra immersion.
Setting up a flight (route, aircraft, flight plan) can take an hour or so until liftoff. Then depending on ATC coverage I stick around and monitor the fight. Once I am out of ATC coverage I either keep it running and monitor it on my mobile while I go workout or spend time with the family, watch shows/movies etc. or I go to sim rate 4 and do the same things mentioned above.
Usually I come to an hour before arrival and setup the arrival, active etc and re-engage with ATC if available.
If I am doing shorter flights I’ll do a turnaround or a hopping flight, everything is linked via ACARS at my virtual airline.
Cheers!