3. "What are you doing Saturday?"
Trust me, I know you are a generous soul, and that most of the time you would love to watch a friend's twins so she can get her hair cut or be the third wheel on an awkward not-a-date-first-date-hang-out. Still, when someone asks, "What are you doing this weekend?," the proper, self-preserving answer is, "I'm not sure yet. Why?" Juuuuust in case the follow-up to that question was, "Nothing? Oh good, do you want to help me sort through my storage unit?" It's not mean-spirited or selfish to give yourself a minute before committing. Friends are friends; but also, Saturdays are Saturdays. Which friends understand.