Drill on the most common sentences within the most common subject domains that illustrate the most important grammatical rules -- in priority order for sentences, domains and rules. Drill, baby, drill. It's like learning the piano or tennis -- largely about muscle memory. No existing foreign language learning products that I know of have fully developed this idea. - Sean McBride

Reading, speaking and writing *simultaneously* -- with close attention to every small detail -- that is indeed highly effective. - Sean McBride