Didn't know that Reagan was an afficionado of the notecard method. He must have had many secrets, but one of them was "a stack of 4 x 6 inch note cards that he compiled over the span of four decades. Consisting of quotes, economic statistics, jokes, and anecdotes, they became the core of Ronald Reagan’s traveling research files." I have just learned this from a a review of the book: The Notes: Ronald Reagan’s Private Collection of Stories and Wisdom (Harper, 2011) edited by Douglas Brinkley. "The cards would feature between five and 10 items and would be written on both sides." This does not seem like a good system. In fact, it's hardly any system at all, but it apparently helped not just his speech writers, but it also helped him remember his one-liners.
Here are some pictures of his cards.