How do you approach people you don't know?

This is probably very lame, but I was basically sitting doing nothing. So I decided I wanted to ask you flutherites something as lame as my life.
How do you usually approach people you don’t know but want to talk to? Someone suggested since people have to take showers everyday, they’d knock on their door and ask to share the shower since theirs isn’t working. .
I just usually stare at the person. I don’t think it gives the desired effect though, I probably come off as a creepy lady. Plus I always tend to make bad impressions. I shoved a whole brownie in my mouth at the same time the person was passing by. Not smart.
What about you? Does it usually work for you or do you end up looking like the idiot I am?

And another time the guy kicked a ball, it was going to fall on my head so I screamed like fudge. Yes, a history of bad impressions.