Women should never ride in the front unless four women are in the taxi and there is no room in the back seat.
Unless it is after midnight, taxi drivers are required to run the meter. If your driver does not turn on his meter after the first 10 seconds, then ask him to turn it on. If he tries to bargain with you for a price, get out of the taxi and take another.
Taxi prices after midnight have to be negotiated. A reasonable price would be to add 1/3 to to 1/2 to the normal metered fare.
In Arabic culture, it is not normal for a man to carry on an extended conversation with a woman he doesn't know. If you are a woman, it is recommended that you keep your conversation with the driver limited to directions. Feel free to act busy with your phone to avoid personal conversations with drivers.