3. Eye contact and smiling
A nice and friendly smile plus eye contact can work wonders. The man you are interested in will feel willing to get familiar with you for sure. Staring at him might feel uncomfortable for both him and you. It is not polite either. So catch his eye occasionally and smile from time to time. After a few eye contacts you will understand if the guy is ready to have a conversation with you. If you see him smile back to you, try and approach him even if he is among his buddies.