So my question is: what do you do in addition to saying "hey" and "bye" when you're on the date with your girl.

I usually hug girls, or kiss them on the cheek.

How should I greet/farewell a girl I've had intensive french kissing or sex? Should I stay with "kiss the cheek" or kiss lips/french kiss her? Sorry for silly question, I never really bothered with that until I've met girl which attracts me more than others, and I want to escalate attraction further (we had 10-15 mins frenchy after two drinks, but no sex as it was in front of her house and she still lives with her parents) and I don't want to scare her off by being too much pushy.

Depends on the girl and the situation.

If its somewhere formal and your wearing more formal clothing like a suit kissing a girls hand is really sexy. If its just a casual gathering then a hug is good. If its the first time youve seen them and are close then a kiss on the cheek is best.

Whatever you do make sure you do it with 100% confidence. A hug can be really akward as can a kiss. Maybe practise hugs, kisses etc on everyone you meet including men until its normal for you.

In a lot of Europe (Italy especially) greating friends of any sex with a kiss on each cheek is the norm. And look how sexy women think Italian men are.