„If you know how to make a girl smile, then you will automatically be more successful with women in general. People like to smile, it makes you feel warm and fuzzy inside and these feelings will be associated with the person who has made you smile. Wouldn’t you like a girl to feel warm and fuzzy when she thinks about you ?

Here are the kinds of smiles you are trying to get:
•Genuine smile
•Compliment smile
•Impressed smile
•Happy smile
And here are the kind of smiles you want to avoid:
•Polite smile
•Weird / “You are insane” smile.
•I own you smile
Situational smiles
The easiest way to make a girl smile is to make use of the environment that you’re both in at the moment and to highlight something funny that is occurring. There is always something interesting, or funny happening if you pay attention to it.

For example, if you’re both waiting in line… make eye contact so that she notices you, and then immediately go into a huge fake yawn hinting that you’re bored of waiting line. This works great if there’s a huge line and no one is talking. The key is to be funny while retaining your dignity. If you make a fool of yourself, you’ll get the “you are weird” smile.

A more verbal approach in situational smiles would be to point something funny out to her. Usually talking about other people or items is an easy way to score a laugh. If you were grocery shopping and you happened to be in the cheese isle, you could say in a serious tone: “This cheese reminds me of the moon”, and then break out a small grin. Its dumb, but it works. ( Here’s a little more information on lines to make a girl smile )

Avoid pre-canned material
Of course, the WORSE way to make a girl smile is to use someone else’s joke or canned material. If it doesn’t come out as spontaneous and natural, then it will trigger the polite smile. What ever you do, do not ever tell a joke with a beginning, a middle and an end. These will NOT trigger any attraction what-so-ever. In fact, what this says is that you are trying to impress her and this will consequently lead to less attraction.

Body language smiles & smiles attract smiles
Sometimes giving a genuine smile will result in receiving one as well. “Give and you shall receive!” The best place to try this is in a setting where you are busy and CANNOT immediately talk to the woman in question. The smile says: “Hello, I’m interested and I WOULD talk to you, but unfortunately I’m busy right now and I can’t, so I might later if you return the smile”. Imagine you were hard at work, waiting tables, lifting boxes, actually doing something… and you saw an attractive woman you wished to talk to but at the moment, just couldn’t. A nice genuine smile would be infinitely appropriate and would peak her curiosity assuming she found you remotely attractive.

If you don’t end up talking to her, then she’ll leave thinking: “Oh I should go back to that place where that guy smiled at me… maybe he’ll still be there and won’t be busy this time” 🙂

Conversely, if you DO talk to her, she’s likely to be much more receptive and excited to get to know you. 🙂 🙂

The worse place to give a big smile as an opener is at a club, bar, party or any social setting. This immediately says: “Hello, I don’t have the guts to talk to you”. In those situations, talk first, THEN smile.

Comedy: Exaggeration and misleading
Assuming you’re hanging out with the girl, exaggeration and misdirection are the best ways to make someone smile. Its the essence of all comedy and it works for professional comedians as well as for you.

If you can get a girl smile, she’ll usually be more attracted to you. All those good feelings get associated to you and consequently, you end up being the guy who makes her feel good. The last and most powerful way to make a girl smile is called using the “cocky and funny” technique. Not only does this technique work every time, but it also triggers powerful feelings of attraction at the same time. Not only will you learn how to make a girl smile, but you’ll learn how to create powerful attraction as well.”

from http://www.artofseductions.com