I'm sure you've heard the idea of "write as you go" a lot in the last few weeks. The idea is simple. Once you gather information on a person, work it into some sort of narrative. It could be a family history, a story, a conference paper, something. It's just to prevent you from throwing everything in a file and forgetting it's there.
I'm adding a second part to that tip. As you write, review what you know about that person. Don't just copy things from your database or file. Make sure that what you're writing makes sense and that you can back it up with documentation.
Why do I care? Because I just followed my own advice. I'm putting together a family narrative. Looking for more sources, I followed the tree a few generations down. And low and behold, someone in my file had the wrong first name. Easily remedy, but it almost sent me off on the wrong track.