You may need to make your "approach" more conversational instead of worrying about the line. I always like the "Juggler" conversational way of approaching and doing things.
I usually tried to comment on something about the situation, i.e. you are standing in line at the store and it is moving very slow. You make a comment about that to get the convo started and move on from there.
I got married about 6 months ago to a doctor and I met her in a book store. I frequented this book store (a Borders) as it was always packed with attractive women and was an environment I felt comfortable in- I love to read. I never rehearsed a line in advance I just made a comment/ observation. If there was not much of a response, I moved on. If there was, bingo and then it was easy to turn it into a 5-10 minute convo and once I got the balls to # close, I was never turned down (collecting over 20 #'s in a 4-5 month period). To give you an example, when I saw my future wife for the first time I was looking at a table of discount books. The sign said 3 for 2. At first glance, I thought the sign said 3 for $2. My comment/ observation was "Wouldn't it be great if these were 3 for $2 instead of 3 for the price of 2. From that it was spun into a 12-15 minute convo. I did not # close the first time as she lived over 2 hours away and I was dating a couple of women that lived closer. But, I kept running into her every weekend. Unbeknowst to me at the time, my future wife was driving 2 hours to come to this store to do the old "unintentional run in w/ me", i.e. oh your here again, wow I just came to get.... Finally, one time I saw her, we talked for close to 4 hours and I got her #, the rest as they say is history. For the record, all the other #'s I got the first time I talked with the woman.
Didn't mean to hijack your thread w/ my story. I just wanted to illustrate to you a way that was successful for me, hoping you can take something and apply it to your situation. I used to be the biggest wimp when it came to talking to women, and then when I could approach and have a good convo, would wimp out on # closing until I got so frustrated w/ myself at having let another hottie escape without me at least attempting to get a #. It is a process that many of us have had to work through, but if you keep improving you will get to a point that it will seem natural to you and you'll put it all together. That is the way it worked for me.