Where is the correct place to use 您 when addressing others?
I've found when meeting people for the first time, they often ask '您贵姓' as opposed to '你叫什么' or whatever else. This is even in informal situations with friends of friends.

Also, when meeting older people, or friends relatives for the first time I would definitely go with 您 - you just want to show your polite character. I've noticed all my friends doing this so I'm not the only one.

Lastly, if you even meet anyone in a business context, then it pays to go with 您 from the outset, at least until you know them better. Just more polite really. 

Hope that helps!