The Johari window is a great self-awareness tool used for personal development purposes. In order to achieve understanding of yourself and others, this tool can be used in a personal or work setting.
First off you decipher what strong character traits you have as an individual (open area), then you allow others to do the same for you (blind spot). There are also traits you do not want others to know (hidden area), and traits you are yet to discover but will so overtime (unknown area).
Try out the Johari Window, and become more self-aware of you traits and use techniques like the SWOT analysis to help you recognise areas of development even further.