The Deeper in the Game blog has a really nice template for a character concept, which I've copied below.
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A «personality trait» «profession/role» trying to «goal» despite her «flaw».
She wants to become «profession/positive trait», achieve «social status», overcome/move beyond «past trouble, mistake, tragedy». She believes in «ideal or personal credo» and can’t stand people who «believe other credo/behave in a certain way». People know her as «reputation» and expect that she will «achieve/fail/become something».
She is a part of «social group», is expected to obey «authority figure», assisted by «friend/group of friends», is opposed by «rival group».
She wants to earn respect/love of «NPC», see «NPC2/rival group» get their just desserts for «dirty deed», help «NPC3» deal with «problem/flaw», fulfill «promise made» for «NPC4», and protect «NPC5» from «personal flaw, danger, other NPC or group».