Recognize that your memories might be biased. How you perceive the world will always be from your point of view. Because of that, your memories of things will always be ever so slightly biased in your favor. It is important to recognize and compensate for this. To recall an event correctly, try recalling it from an objective point of view.
Try using mnemonic devices to aid in recall. A mnemonic is a way to remember information. One mnemonic is word association. Think of a word or phrase you are familiar with to remind yourself of the thing you wish to remember. Rhymes, songs, and humorous images make good mnemonics.