I'm curious about how one can go about improving their Gitcoin passport score. Could you elaborate on some strategies or actions that could potentially boost this metric? Is it primarily driven by contributions to open-source projects, or are there other factors at play? I'm particularly interested in understanding the weightage given to different types of contributions and how frequently one should engage in these activities to see a noticeable increase in their score. Additionally, are there any pitfalls or common mistakes to avoid when striving to enhance one's Gitcoin passport score?