Here are a few ways to say no politely: “Sounds wonderful, but that is not part of my work focus right now.” “Sorry but my current commitments mean I cannot take that on.” “It sounds amazing but I wouldn’t be able to give that the attention it deserves.” “I can’t help you right now but I can schedule it after X date.” “Sorry it is not my policy to do X.” (People respect policies, even ones you have made up yourself!)