To start a date with a girl, simply go to her house.
However the girls will only be home at certain times.
This counts as a failed date, even if you're on the way home from an otherwise successful date. If it does, date her immediately until it is above 0%.
A higher minimum is adviseable, but at the very least keep it above 0%. If you let a girl's respect for you reach 0%, and then date another girl, your current date will always once be caught by a jealous date whose respect for you is 0%.
Take her to a fast food joint, bar, diner or restaurant (some of these may not show up on your map until you start the date).
Each girl will have her own taste and may not like the place you take her.
In this date, you take your girlfriend for a drive. Understandably, the relationship meter goes down by a huge amount and will be difficult to get back up to where it was.
You have to hit the buttons as shown as they pass though the circle, as in the Life's a Beach mission. Hitting her once might not fail the date, but hitting more than once or shooting will instantly end the date.
San Andreas introduces the ability for the player to pick up dates and go out with them.