Visualize yourself in a different job. Do more than just think positively. Picture yourself in the position you want. By thinking as if you were already in the job you want, you're more apt to convince others that you're right for it. Improve your communication skills.
Good communicators listen carefully and speak effectively.
The more you pay attention to what others in your grapevine say and the more you think before you talk, the less likely you are to say something inappropriate when discussing sensitive issues. Note and analyze the information flow through your grapevine. Once you've established a solid role in the grapevine, take note of how the members interact with one another. Information is power. Whoever gets key data first generally has more influence than employees who receive it later.