Saying no needs to be more regular than irregular in a leader’s life. Leader’s influence other people. Oftentimes leaders will be inundated with good opportunities that aren’t crucial to the mission or a good steward of their skills or time. Here’s five ways to say no:

• The awkward pause. Pause for a moment—maybe 2-3 seconds—before delivering your response.
• The soft “no” (or the “no butt”).
• Let me check my calendar and get back to you. This gives you the time needed to reflect and ultimately be in control of your decisions
• Email bouncebacks. People will be accustomed to your temporary absence and non responsiveness. For me this looks like putting together a sermon series, having an off-site team meeting, or attending a conference. 
• Say, “Yes. What should I deprioritize?” This lets the person know that something else is going to have go (i.e. communicates trade-offs).

Taken from Greg McKeown’s book Essentialism: The Disciplined Pursuit of Less.