here's what i do, and there are other way's, but this fits my set up.
i make a nice sized starter for a lager (2 quart). once i chill the wort, i aerate for 2-3 minutes, then add my yeast starter. once i see signs of activity, then i move my primary to the chest freezer, and gradually lower the temp to the fermentation setting (around 50-55 degrees). allow it to feremeent for about 14 days, then raise the temp to about 68 degrees for a 2-3 day diacetyl rest. then rack to secondary and lower the temp by 2-3 degrees a day until i reach 30-32 degrees. then i lager for a minimum for 4 weeks, longer the better. but, no more than 6 months for me.
the quick change in temp for the yeast may shock it, and it COULD result in off-flavors, and will retard fermentation. just based on my experience and reading.