[fudged71]

It's actually hilarious when some store employees/managers will desperately try to get your attention even if you're wearing headphones to tell you about their sales. If I want to be left alone then leave me alone!

(I only did this once but it was very eye opening)

[ben-schaaf]

I've generally found that when headphones aren't enough to dissuade people from talking to me, I start intently looking at my phone like I'm reading an important email. It works wonders even if the screen is off.