Always show up five minutes late; your date will never be on time, and it will reduce the amount of time you have 
to wait for her. Bring your date's cellphone number; if he or she doesn't show up in 20-30 minutes, call. Chances 
are you'll only get an answering machine; if you do, leave a message and go home. If she doesn't show up in 30 
minutes, chances are she's not going to. Needless to say, never reschedule a date with a no-show, no matter what 
the reason. The odds of there being a legitimate reason for not showing up for a first date are about 99 to 1, against. 

But on the off chance your date actually does show up (it does happen sometimes...), buy her a drink and then sit 
down to chat. You can follow up on topics you talked over the phone, but generally conversations either flow, or 
they don't. Don't talk about very personal things, or things she might have no interest in (very technical details of your 
work come to mind); gauge her level of interest and response and try to talk about things you know she's interested in. 
If she responds a lot to what you talk about, then keep talking; if she responds very little, switch to another subject. 
Your objective is to find something that will get her talking, to probe different topics to find what she's interested in. 
Unfortunately, some women (and men) have nothing that they're interested in, which makes for a difficult conversation. 

Don't talk about yourself too much, or about her too much; keep track of how much you spend talking about each
other, and make sure there's a reasonable balance. If your date asks very little or nothing about you, that's a bad sign
--it shows a lack of interest. If you're running the conversation all the time try pausing and see if she steps in; if not, you 
can even ask her "Now, what would you like to ask me?". (I did this one time, and got very little in the way of response, 
which showed me immediately that I was with an uninterested or uncommunicative person.) 

The best topics to talk about are hobbies or common interests, if there are any; asking about his/her work is ok, if his/her 
work is interesting (although usually, it isn't). Also, if you're a man, occasionally compliment her, but not too much; make 
eye contact from time to time, and occasionally touch her hand or arm if the conversation is going well. If she's not very 
talkative, she's not interested. If she is very talkative, she may or may not be interested. 

If you can keep the date going for 2 hours, that's a good sign. If the conversation starts to flag that's also a good sign 
to call it quits, to end your first date while things are still going well; don't try for an endurance record. 

If you find her totally uninteresting and uncommunicative, you should end the date early, after 20-30 minutes. There is
no sense continuing if you are not interested, you're just wasting your time and hers. 

By the way, if he/she ends the first encounter in under an hour, pleading a previous appointment, he/she is definitely not 
interested. One time a woman did this to me, remarking, "Usually I use this as an excuse to end a date early, but in your 
case I really do have to meet a friend of mine, but I really do want to see you again!" She seemed so earnest. Of course, 
I never heard from her again. 

Also, if your date looks nothing like her photo, or is heavy when she said she was thin, I wouldn't spend a minute with 
her. If she (or he) significantly deceived you about her appearance, I would tell her (or him) so and immediately leave. 

If you're interested at the end of the first date, say you'll call her; otherwise, simply say you've had a nice time meeting her,
but make no mention of calling her again. You should never, ever ask for a second date at the end of the first date; it will 
make you look too eager, and that will turn some women off. You should act moderately interested, saying something like 
"Thanks, I had a great time, I'll be in touch" if you enjoyed yourself, nothing more. A goodbye kiss is recommended as a
textbook response, but it's actually optional, depending on whether it "feels right". Nothing is worse than a forced, 
perfunctary kiss. 

You can always tell if someone didn't enjoy being on a date with you; but you can never tell if someone actually enjoyed 
being on a date with you. The only way to tell is to ask for a followup date.