I want to set up apt repository priority ordering in Linux Mint Debian Edition 2012.04. In
/etc/apt/preferences the order should be: LMDE -> Debian testing -> Debian unstable. In other words, I almost always want to use packages from LMDE semi-rolling repository, and only sometimes get them from testing and unstable only when absolutely necessary.
I looked at http://forums.linuxmint.com/viewtopic.php?f=201&t=78882 and http://forums.linuxmint.com/viewtopic.php?f=141&p=379226, but still have not been able to get repository priority ordering to work correctly.
What is the best way to do this?