In "Blue Like Jazz," Donald Miller emphasizes the importance of expressing feelings to someone you like. He suggests that while it can be awkward to confess your feelings, the regret from not doing so far outweighs the discomfort. Taking that bold step can lead to personal growth and clearer relationships.

However, Miller also warns against over-persistence when the feelings aren't reciprocated. He shares that once a girl makes it clear she isn't interested, it's best to respect her boundaries instead of continually pursuing her, as this can lead to discomfort for both parties. Understanding when to step back is equally important in the journey of relationships.