Ask.... just ask.
I will give you two scenarios to illustrate.
#1- I was buying a bag of coffee beans at Dunkin Donuts. As the cashier rang up the bag I jokingly said, "Hey, want to a throw a free donut in with that?" She said, "Sure what kind do you want." Free donut... so yummy!
#2- Jon threw away the charger for his bluetooth... yes I did say threw away. He asked me to call about getting a new one. When the operator asked what happened to the charger and I told him it had been thrown away, he didn't even hesitate, "One moment and I'll get your address to send you a new one." This sounded like a scam to me, "How much is that going to cost?" I queried. "It's free of charge, this time only." (in other words don't throw away useful electronic pieces in the future) Free charger... Jon is so happy!
I'm not saying we should try to mooch off of people all the time and beg for free stuff, but sometimes just asking can help you save.