Gage the situation. If I'm at a pick up joint, then I use pick up type of lines like "Hi, my name is Ed and I'm a Libra" or something corny and funny to break the ice.
If I'm out of that environment, then I try to use some simple honesty, not too strong, but something simple and subtle like "hey, lets hang out".
This worked once (the only time I've tried it)
I got caught staring at a girl and she looked at me and said "excuse me, can I help you?" as stunned as I was, I answered "I'm sorry, my eyes just a natural tendency to wander toward beautiful things". She couldn't help but blush and we struck conversation.