Common mistakes to avoid while trying to quantum leap include setting unrealistic goals, not taking action, and fear of failure. It's crucial to set achievable goals and create a plan to achieve them. Procrastination and lack of action will hinder your progress, so take small steps towards your goals every day. Fear of failure can also hold you back, so embrace failure as a learning opportunity and keep moving forward. Lastly, avoid comparing yourself to others and stay focused on your unique journey.