I don't like saying no. Especially to people. However, I've been finding myself doing just that. In improv, I am still very confused at the UCB approach which tends to lead to more "no's" than I am comfortable with in long-form improv, at least at the lower levels of experience. In life and improv I just want to go on an adventure, and when you "yes, and..." things, you build on that adventure. However, if it were my choice I would have every scene in space, so perhaps some grounding may be very useful.
I just said no to an acting opportunity because the subject matter did not quite gel with me. As in I was mostly okay with it, but I would not have wanted to show it to some of my family, so I said no out of principle. It was to a friend with over 20 years experience in films. That was a big and unusual no for me.
No and yes are both powerful words. Destructive and creative.