It's super corny, and possibly just a placebo, but I've used this for various things that induce social anxiety or anxiety in general. Sit back and think about the event, as you feel the anxiety growing, try to focus instead on what might be exciting about it
For interview, the prospect of a new gig, for going out with a group or other social engagement, anything fun there, for meeting new people, finding a shared interest with someone
I read somewhere that the feelings of anxiety and excitement can be very similar, so you can almost redirect the anxiety to something more beneficial. It doesn't help actually talking to people, but it helps get you out of your head and into the moment. Ymmv
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