Between On and Kun reading. What should come first when memorizing?

When memorizing Kanji, should I remember On then Kun or Kun then On?

Interesting question! To be honest, my method for learning kanji has been to learn the vocabulary, rather than to memorise the readings.  Some of the kanji have a lot of different readings and it can get quite difficult to remember them all.  If you learn enough vocabulary though you tend to get a good feel for what the readings are over time.  I'd be interested to hear what other people's opinions are.