1) Look for people who know you. Avoid them. Ideally, find a time when they’re in another part of the venue. However possible, ensure they’re not by the door. This is especially important for known smokers.
2) When known entities are out of sightlines, tied up in conversation, or far enough away, reach into pocket with a look of intrigue.
3) Pull phone out of pocket and change expression to surprised puzzlement. Both are key. You are surprised at receiving a call and puzzled as to why they are calling.
4) Pick up phone, pretend to talk while mostly listening, and inch toward door.
5) When close to door, be sure to have all personal belongings. If not, discreetly gather them. Yet do so in a manner to suggest you’re just stepping out, not leaving permanently.
6) Say into phone, “I’m sorry, I can’t hear you in here. I’m stepping outside,” or something to that effect. Make hasty exit.
7) While pretending to chat, eye exit and surrounding perimeter to ensure there is no one around to whom you will need to explain your departure. You should have covered this in step one.
8) Continue future conversation until you’re a comfortable distance from the venue.
9) Congratulations. You are now free.