Ever think the people around you have a fixed opinion of who you are? Do you think this opinion is set in stone?
While consistency is a very important trait in a leader, it is not the foundational trait. A leader must, first and foremost, know who he is and be true to himself. Once you can find a way to let your personality, beliefs and goals shine through every action you take and conversation you have, you'll find yourself being consistent all the time, simply because you're being yourself!
Start your road to becoming a great leader by simply finding out who you are and trying to live in a way that compliments your goals, vision and mission. It might seems like a small step, but it can often be the most noticeable step to those around you. give them some time to get used to the "new" you (although you and I know this "new" you has really been you all along!) before doing anything else.