I tend to log hobbs time (which starts moving when the engine starts) since the time between engine start and moving off is no more than 30 seconds. On return I stop the aircraft and shut down within 30 seconds of stopping. Since hobbs is only accurate to the nearest 5 minutes anyway I can't see that this makes any difference.
My tech log gets (take off to landing) times to the nearest minute which I believe is what determines the maintenance schedule. Conveniently my new panel mounted GPS records this time for me so if I have forgotten to note the time on take off then I can get it from there.