I get paid per hour flown however, the school I work for schedules 2 hours for each student so that equates to around an hour of unpaid ground time which is usually spent with the student in some way or another.... I prefer not to do more than the recommended 15 mins brief before a flight and that's for the students benefit - believe me, I can babble on for hours if you let me, but I'm not gonna max the student out before we get airbourne.
This unpaid hour is also taken up by refuelling the aircraft, paperwork, student records, etc (where does all the time go?!) which we all accept as part and parcel of the gig but it's hardly fair. On busy weekends we should all be paid a set wage because even if a student cancels and we have a free slot, our services are invariably used up in some other way by answering the phone or fetching an aircraft back from maintenance etc... Best thing to do is to sod off to the cafe really but that's only going to cause friction amongst collegues who are equally poorly paid.
VFE.