From previous experience with several different employers over the years, the general rule of thumb I have come to use is to let the machine run down for 15-20 minutes before moving it FULLSTOP!!!, or simply switch the master switch back on and allow the instruments adequate time to run up before moving. A few pilots I have worked with in the past have also shut down the machine and left the master and strobe light on (good reminder that battery is still on) and move the machine once the blades have stopped turning, but the instrument gyros are still spinning at operating RPM.