Have a plan and use friends: This is all predicated on the fact that you can carry on a conversation in the first place.

Ask girl to lunch (unassuming place, non threatening). Go to restraunt or food place (nothing fancy, think local walk up and order joint). Speak with cashier/server before hand and ask them to greet you by name and have quick conversation with you, like they know you from going to the place but not to well. Offer to tip them for helping.

Have 2 friends (preferably one girl)be at the place (separately) if she goes with you have each friend about see you (seem excited) and come over to talk to you and compliment you say they wanna hang out etc. this establishes you as both friendly and somewhat popular with random people running into you and liking you. Have each friend be polite to the girl. Have the friend who is a girl talk about how funny, fun, etc you are (but not over the top).

Ask the girl lots of questions about herself throughout the lunch, be interested and probing but not creepy. Pay for lunch.

As your walking out says how nice it was and ask if you would like to have dinner later in the week.

Text her on e after this saying you had fun and look forward to seeing her again. Do not text her or call her for 2 days. If you see her thats fine talk and be cool. Third day call her. For dinner. She should be intrigued and not on guard because you have established friendly people know you and you are pleasant and at least good for a free meal.

Have same thing happen at dinner, with server and friends or group of friends. But do not sit with friends see them, chat, introduce girl and then sit away from friends.

Same conversation answer her questions about youa funny appropriate anecdote here or there. But always go back to her story her thoughts ask her question about her stories and such. Have server bring you the check and call you be name etc. profusely thank the server and tip appropriately.

Walk her to her car (unless you feel ballsy enough to pick her up to big with (depending on how lunch goes).

The key is be yourself, be pleasent and conversant, and have people around to establish your open and friendly manner. After all this, ask her to pay for her portion of the check. When she asks what the cut is, look her right in the eye and say " tree-fiddy"