I have to say most men I know are not good with girls. They usually give them to much value (we are talking about the ones they find attractive, of course). The worst thing ever for a girls (especially hot ones) is to sense you are just only after her looks and, sadly for guys, is the most common mistake they make.
That's why girls usually don't meet interesting guys outside there social circles. Most of relationships start within social circle, not with a cold approach on the street or bar.
I think the most essential and harder thing a guy most improve to get good with girls it's their conversation skill. Once you accomplish this you are on your way to become great with girls. Being able to continue a conversation with no problem will free your mind of this really heavy task to concentrate on the rest of stuff.
I still lack in conversation skills. I need to talk to more girls because I have noticed I really attract girls and being able to improve this will mean that I will be able to hook them all into the interactions. Then, I will be able to practice other things that, for me, are way easier (escalate, move, etc.) because I know they are attracted to me so I'm confident enough to push things. I'm pretty sure I'll get so much better sooooooo fast.
For any guys struggling remember to practice talking to other people to improve on your conversation skills. It's easier if you talk to guys like a cab driver. Try to hook them. It's not exactly as hard as with girls but it will help you. Don't talk to much when you think you have give enough, see if the stranger invests in the interaction, etc. Treat it like hooking a girl.
And, stop looking like the image Drck posted!
Cheers!