To use bet sizing to tell a consistent story in poker, you need to make bets that align with the hand you're representing, while also considering table dynamics and your image. This involves varying your bet sizes to create a believable narrative, making your bets transparent enough to be believable but deceptive enough to conceal your true hand strength. By maintaining consistency in your betting pattern, you can effectively use bet sizing to tell a story that deceives your opponents and helps you achieve your goals at the table.