Before you can become good at saying no, you have to know what you're saying yes to when you're saying no. Every opportunity that you pass with a no is really saying yes to something else. 

And if you feel like saying yes, ask for time to think about it before providing an answer. It...

Speak up when your workload is too much. Tell your boss if you are stretched too thin or when you regularly work too many hours. Talk about what you can reasonably get done in a week.

Also, don't say yes to everything. If you have a hard time saying no, don't respond immediately. Instead s...