for me its:

1> turn on engine

2> turn on blower

3> if mainit sa loob, open windows for a minute or two.

4> turn on the compressor, via thermostat. walang a/c button yung fx eh.

i do this to let the engine spray itself with oil, so when i activate the idle up system via thermostat its less wear and tear.

pag ioff naman engine, off muna compressor via thermostat pagdating sa bahay then off ng blower then engine after parking the vehicle. opening the gates, vehicle entry, gates closed, that takes a minute at least. by that time tuyo na evaporator. =)

its more of taking care of the engine (start up) and the vehicle itself (iwas amoy mabaho/kulob).