I've been working on simple ways to meet people. Here's one way that I've practiced with success. But first things first. This will not work if you are not fun and relaxed in your interactions with strangers.
So be cool. If you don't know how to be cool then sign up for my Conversation Camp. There's no shame if you need to learn to be better in conversation. Most people try to be the dictator of the conversation. They're so worried about getting something out of her they squeeze to tightly. This is like trying to squeeze sand in your fist. It just pours out.
Make sure you talk to the staff there at Starbucks. Make them like you. Tell them that you want to have their job and it must be fun to talk to so many people. Make them feel good. This alone can help you meet an attractive person. If they like you a lot you can ask them to drop a chocolate off at someone's table with your compliments. Then wave and mosey over and tell her you thought she could use a pick me up. I mean chocolate is the sexiest food so this is already in a good spot.
Another way to meet girls there at the coffee shop is to sit at a table within conversational distance to those cute, bookworms. Say, "Excuse me, do you know what time this Starbucks closes?"
As she fumbles around for the answer. Squint a bit at her and interrupt her and say, "You have the most intelligent looking eyes," or "You, uh, are very attractive," or "You have a sexy voice."
Say this as if you have just discovered it. Believe it, over-act it. She must see that she has effected you.
She will blush and say thanks. Just keep going. Don't make it a big thing. There is much power in showing your attraction but not getting hung up on it. Ask her name and tell her about the story you're writing. Tell her you find the two of them interesting and would love to hear their stories. BE COOL. Talk to both girls if there are two. Don't ask too many questions. Be funny. Be charming.
After a few minutes say, "I should let you get back to your work. It was nice meeting you. I don't know your situation but would love to see you again."
If she likes you she should share some contact details.