When writing, keeping track of things is important. This is especially true when it comes to your characters. You never know when it will be important to recall the date someone died and you don’t want to accidentally change your character’s physical attributes. Those kind of problems can cause a break in continuity for your readers.
To avoid looking back through all my writing when describing a character, I created a spread sheet to save my sanity. It was a cheap (a.k.a. free) and easy solution to organize the characters in my stories.