TL;DR: How do you approach and escalate with a girl at a party in order for her to grind you?

Clubs are reopening in my country and I want to have fun. This sub is said to help you connect with women "whether the goal is casual sex or a relationship". In my case, I want something even more casual than sex: just catch some twerk when I go to a pool party with my girl friends or when I go clubbing.

Some elements on how to approach women at a party apply to my situation: making eye contact, smiling, having fun... But I would like to know more specifics. How exactly should I approach? How to transition from platonic dancing to grinding? How can I grind with a female friend?