I either get fatalistic (I'm going to die so I might as well enjoy X activity while I'm doing it since it will be my last/is going to kill me/I'm going to be mortified/embarrassed :-) and focus on the "good" things that are equally possible (I might meet someone who is pleasant to be/talk with) or I work on the worries and make sure they can't/don't come true (make a sign with the date/time and print out a map how to get there, do a "practice" run driving there to see how much time it takes, what is difficult about it, etc.) and imagine various conversational things I can say, get a "friend"(s) involved in what I should wear and willing to talk with me about how scary the event is and help relieve some of my anxiety, etc. Remembering what others have said and conversations with them (even from here, online) helps me as I feel less "alone" when I'm at the event itself and I can remember the other people and the conversations and move forward a bit better.