I never believe in cold approach because i think its ineffective ,unless you are super hot.Instead,I look around to find potential target.Which is:

_Sitting/relaxing:People will more open when they're in relax mode.

_Alone:Not become a bother to a group,or make her shy

_Topic:she got something that I want to know about.So we have something to talk.Never random compliment or cheesy lines. I follow this rule and got a high chance of success.What's your opinion?