Quick No , Long Yeah
Daniel Kahneman, the Nobel Prize-winning psychologist, has a rule where he never says yes to anything on the spot.
People-pleasing had him making too many commitments. He says something to the effect of: "Thanks for the invite. I don't say yes to anything on the spot, but I'll let you know if I'm interested." Turning the choice into a rule lowers the pain of rejection for others and makes the decision easy for you as well.