@sakyo:
Depends on the setting
In a once off setting ie friend's birthday party, work function, just be polite, maintain a bit of chit chat, after a few minutes, initiate a conversation with another person and move away
A friend/acquaintance that you do not like to hang out with, "busy" to all invitations to one to one meetings, passive communication when met as a group ("yes" "wow really" answers, do not fuel the conversation), again still be polite about it
If it's someone you not attracted to but hoping to go further with you, if they make their intentions clear, be direct as well, explain that you are not interested in anything more than friends. If you feel like they want to take things further are you are not interested, it helps mentioning you are interested in someone you recently met, or suggesting a feature that you are attracted to but that person lacks perhaps?
:love: