“Accost” appears to be a really bad translation of 招呼. Another Chinese guy here made the same mistake last week. As the others have explained, “accost” is very negative in English. A better verb would be “approach”, “say hi to”, “introduce myself to”, or “meet”. In answer to your question, it depends on what exactly you’re looking to accomplish, as well as your personality, her personality, and countless other details of the situation. What would you say in Chinese? By the way, what you say is actually not that important, because girls will mainly respond to your non-verbal communication — your body language, eye contact, and tone of voice.