Want to make your girl squirt?
Almost any girl can squirt, but you need to take it slow, expecially by not skipping on foreplay. May sound boring but that's the way it is, unless a girl is not really turned on on a subconscious level, there's no way she will squirt.

Now, once you are both relaxed and started your sex games, she's wet and excited, you might want to go down on her orally, before sliding your finger(s) inside her. You use your middle finger a finger next to it, palm up, and once you're in, feel your way around in a "come here" manner, until you feel the Gspot (a bit rougher than the rest). You can stimulate her Gspot in many ways, from flicking over pressing to making small circles around etc, observe how she responds to teasing, and slowly make your moves more intense..
When you see that she's close or maybe hesitating, it's time to make her "let go" and tell her that you want her to relax completely, enjoy to the fullest no matter what happens. Once she does start squirting, keep doing what you were doing until then, do not stop suddenly or move away!