I met my last girlfriend while she was at work - she waited tables at a bar near where I live, which is a college town so there was never a shortage of guys trying to lay some game on her: HB8, tan, blonde, tattoo on her lower back, the whole works.
Anyways, I had no dj plans in mind when I went in there, all I wanted to do was to do some reading and chill out a bit, maybe have a few beers...I sat down, she came up and asked me how I was doing, her intial tone indicated that she was tired, and that I was just one guy out of hundreds that she would see that night - I looked up and gave her a huge smile, told her I was doing great, and asked her how her night was. I saw right away the effect my smile had on her, because she gave me a huge smile back and said she was doing fine, just been a long night and all that - we made small talk and I ordered a beer, and she went off to see to her other tables....
I pulled out the book I was reading at the time and read for a bit, and didn't give anything else much thought...at one point I happened to look up and she and another co-worker (another HB8 - gotta love college towns) were both looking at me from across the bar! They both looked away giggling, I shot another smile at her and went back to my book, however THIS time instead of reading I started to formulate a plan...
About 3 minutes later she comes over to me, I figured that it was just to see if I wanted another drink, but she sits down at the seat next to me puts her hand on my arm, and asks me what I'm reading! I'm thinking "Holy sh*t...is SHE hitting on ME!? For the love of all that is holy, don't blow this, Kid!" For about 5 seconds there I didn't know what to do, but I quickly recovered and gave a quick rundown of what I was reading, (Mystic River) then I got right down to business - introduced myself, asked her how long she had worked there, how she liked it, etc, etc. She commented on the fact that I was in here alone, reading a book, which apparently nobody ever does. This alone made me stand out! Apparently you have to seperate yourself from the rest of the herd - but then again, isn't this the case all the time?
Picking up waitress can be a true test of ones dj skills - most of the time you're just a number to them, and they know that being flirty = more tips, so you never know if they are being sincere or not - the trick is to make them remember you! Avoid the cliche pickup lines, they've heard them all before, trust me. Bringing a book into the bar that night instead of a couple of buddies got me 3 months of off-the-wall sex with a 21 year old HB8 - and we still get together very once in awhile. It may be a bit different for you in a restaurant setting, but the premise is still the same. Best of luck!