I have been using an interesting tool for character development lately. It takes some time, but it is a lot of fun. It basically helps flesh out some key aspects of a character before ever writing a word. This helps keep your characters human, consistent and interesting.
It's basically a table that looks like this:
It is really helpful for me and a lot of fun to execute this prior to writing a sentence. The Notes section can be where you record background information, history, etc. The Notes section can become pretty full throughout the writing process.
Tools are fun to use, but sometimes the right thing is to decide not to use the tool. It's all part of the creative process and using the right tool for the right job. I have derived a lot of benefit from this one though, so I thought I would pass it along.