Short answers work best. "oh hey do you have any plans this weekend? “Yes.” Conversation over. Someone asks you how you are, your answer is “fine, thank you” and you move along. You’re polite and you’ve satisfied all they’ve given you. It won’t work all the time, there are some people who are more interested in talking at you instead of with you. For those, I recommend starting the conversation with an exit. “Oh hey, I’d love to chat, but I only have a couple minutes.” You can now walk away pretty much whenever and it’s not like you didn’t tell them, it was the first thing you said.