Especially good if you leave your lager on the primary yeast until all fermentation has ceased. Keeping the headspace on your lager to a minimum when you rack is good as it allows the co2 comming out of solution to blanket your brew and protect it for the long cold lagering peroid from o2.
Another note is starting your lager at higher than lager fermenting temps. This will cause you to get more fussels and esters out of your yeast than you really want in a clean tasting lager.
If you haven't already read this book, http://www.howtobrew.com/
then I recommend you have a look at it, especially regarding the lager section.
Cheers and good luck