just be yourself.
don't overthink every single one of your actions.
If you're not used to holding doors, then don't.
if you're not used to pushing chairs in (I've never had this done to me and would really give you a "you've got 3 heads" look if you attempted it with me), don't push her chair in.
do what feels comfortable.
if you're going to constantly overthink everything and wonder 'what should I be doing/how should I be acting right now' you're not going to be comfortable, relaxed and most of all enjoyable.
I'm not saying belch and scratch your crotch like you do in front of the tv at home either.
the point here is not to bait her by being someone you're not. you'll only disappoint her in the long run.
