Keep a journal.

Jotting down even one of today’s experiences in a diary not only increases the likelihood that you’ll remember that experience in the future, the information you record can serve as cues for triggering recollection of whatever else happened today. Psychologist Willem Wagenaar kept a daily diary for over six years, recording 2402 episodic events. When a colleague later tested his memory, they found that, if given enough cues (it often required more than one), Willem could recall 80% of his daily events from the past six years. Keeping a diary works!