I was once advised that if I found myself lost and alone in the jungle, and provided that I had the correct ingredients, I should mix myself a dry Martini made of one part Gin to one part Vermouth. Even before I'd finished the shaking (not stirring), someone would suddenly arrive telling me that I'd done it all wrong. Voila!
Another version of this advice comes from Australia. If one should find oneself lost and alone in the outback, one should start playing 'Patience', and, again, within seconds someone will appear over your shoulder advising that 'the red six goes on the black seven'.
Personally I found the very best 'ice-breaker' was having a puppy. It was amazing how many people would stop to stroke a small cute scruffy mutt, and have a chat (I'm known to do this myself). Pleasant in its way, but getting from A to B was a bloody nightmare. I should add that this was based on experiences in England/Wales; not in France.
Samuel Johnson showed wisdom on almost every subject, including that of being alone; he advised "If idle be not solitary, if solitary be not idle". Wise words indeed.