How To Be A Bitch

I need to figure it out. NOW. Some people are probably born more assertive and unafraid of hurting people's feelings than others of us. I'm not good at it. I'm kick ass at being passive aggressive. Yes, I do! But to just outright tell someone "Knock it off NOW"...unless it has to do with my kids, I don't like it. I don't like confrontation (most of the time...I guess sometimes I go out looking for it)...and I'd rather hide than tell someone "DON'T CALL ME ANYMORE."
I see this in my sister too...we're "too" nice to people, and sometimes we attract folks that we don't mean to. You know it...you can see it already....the old man in the bar that we smiled at because he was smiling at us, next thing you know he's siddling up, buying us a drink. Okay, fine, it's been awhile since that occurred. But it's the same thing. Hanging out with people, laughing, having fun, and they might like it too much. Michelle gets this way more than I do because she's in sales. I don't get it so much now, but I have 1 leftover from a long time time. And I'm going to make it go away because I'm done. Over it. I'm going to release that "friendship" (?????!!!!!).
But....ugh.
I wish I knew all the rules. Who it's okay to be nice to, and how to be a bitch. I'm going to request that for the rest of the day here at work, I am referred to as Lucy Wench. Maybe that will help me grow a pair. :D