Here’s How to Say No to More Projects

You're juggling multiple projects, all on a tight deadline, and are just about managing it. Just as you find a minute to take a break and do your anti-carpal tunnel syndrome stretching, your manager comes over with another super-important project with a very close deadline. You want to refuse but aren't sure how to say no. You don't want it to cost you future projects or maybe even your job. So what do you do?