We all know that saying no is a necessary part of keeping a healthy schedule. Take on too much of others' work and you lose your ability to manage your own life. To get an idea of just how important that balance is, try keeping a "No List" of every time you told someone no.
As NPR Creative Director Liz Dancio explains, your time can only be used in so many ways. Keeping track of every time that you told someone "No, I won't film your wedding" or "No, I don't have time to help you label and archive your underwear collection" can help you see just how much time you're protecting. She even takes it a step further:
When I say no (e.g., conference talk invites, "pick my brain" invitations, jury solicitations), I immediately add my regret to the No List. I nurture this growing list of no-things, adding category data like dates events would have happened, themes, and date turned down.
Suddenly, I'm making list of cities not seen, aeroplanes not embarked, and time saved, rather than time taken away. Several months later, I have a made a substantial something. It's how I've marked time.
Keep in mind that every time you say "Yes" to something, you necessarily have to say "No" to something else. It may be sleep, your own spare time or other events you wish you could have gone to. Every time you say no, write down not only what you said no to, but what you would have missed out on if you'd said yes, if you want to keep some perspective.