Be yourself will be the first most important thing you need to do.
When you are not yourself then you tend to make mistakes as you may be trying too hard to make a good impression. Once you are calm then it will be much easier to impress the other party.
Next will be doing what you think you would feel if someone does that to you. If you feel uncomfortable or not nice if someone does it then don't do it. It is always better to imagine someone doing what you are thinking of doing for that person and if you like it, it will be likely to be good.
I always like to put myself in other person's shoe if it was to be done on me.