When you're at work, if it's a girl you work with then she should just know you or you could be like "Hi I'm_____ and I work right over there and couldn't help but notice your lovely ____________ (cubicle, shoes, watch. Just don't mention anything near her chest like a necklace or her shirt) " But if its a girl you are helping at work that you don't work with be like " Hi I'm _________, can I help you with anything?" Then just kind of hang around and compliment her, but don't come on to strongly, because then girls get creeped out. At the mall, just compliment her (using the tips in the other parenthesis) say something like "I noticed your smile and had to tell you how beautiful it was. I'm _______ by the way." So yeah. As for being shy, try having a group of friends around to boost your self confidence, but don't let them come with you to talk to the girl because then she will feel intimidated.