I'm actually only a couple of hours into my training, and those 2 hours were a year ago so I'm pretty much starting from scratch.
Whoa..... Before we start hanging, drawing and quartering IMC instructors lets just take a step back. WHILST I WHOLEHEARTEDLY CONCUR with the carrying out of flight instrument checks before departure and checking of the nav stack as best you can I do believe in not overloading my students too early.
With my students, second sortie is still developing basic IF skills on full panel and partial/limited panel and intro to completing the basic climb,cruise and descent checks whilst still keeping the plane under so sort of control. All of this is done (where possible) in VMC under VFR without reference to any VOR's, ADF's, DME's or GPS. I do, however, avail myself of a traffic service when operating OCAS.
3rd hour is unusual attitudes, compass turns, timed turns, ATIS etc .... still nowhere near the nav stack.
Any IMC student who is asking what checks they should be undertaking for the basic flight instruments / electrial systems prior to departure, IMHO, should not really be embarking on the IMC course - rather they should be seeking out their PPL instructor and asking for a refund.