For the most part, my response to recommendation 1 is: this won't be much use. It is hard enough remembering "the bottom line" without also remembering the source or evidence. Most fact-learning occasions call instead for a snap judgment on the quality of the source or evidence, followed by accepting or rejecting or setting some quasi-probabilistic attitude toward the information, and then spending no more mental energy on the evidence. In those cases, the evidence is usually soon forgotten. So, most fact-recalling occasions are not going to reveal my reason for the alleged fact.

Obviously there are exceptions. If the information is controversial and I intend to share it, then I'll try remembering the source. Or better, bookmarking a link or taking notes.