Amy's tips #1: dealing with awkward academic encounters

There is one invaluable social-graces tool that can almost always be used with great effect in one particular situation:
Trying to announce your departure to a superior (like, say, a professor) who is engaged in other conversation without rudely interrupting. Yes, I speak of the humble "arm touch." A nice upper-arm brush will usually get a turnaround, the moment eye contact is established, breathe a quick "I'm about to go, but I just wanted to say goodbye/thank you/I'll email you [whatever]" and the whole fidgeting-adjacent-to-the-conversation-circle charade is over.

I have passed this wisdom to many a timid undergrad at a department reception. Go forth, and use your power for good.