I started attempting to "steal sets" with one of my wings last week (for sport/science) and I've done it a bunch of times since then. It's a REALLY good exercise for a couple of reasons.

  1. [If you win] They seem more intimidating or hard to pull off (at first), but if you can go into a set and "out-game" other guys then it'll be easy to go approach other girls who you don't have competition for. It also will boost the shit out of your confidence and makes you realize that you really can open ANY set regardless of how difficult or intimidating it might be.

  2. [If you loose] This is what happened when we first did this, the guys seemed visibly panicked (subtle but noticeable), but they successfully managed to keep the girls by introducing us to everyone and then eventually pulling the girls away, even though we came in high energy and the girls were completely focused on us at first.... So by observing what other guys do when a rival male enters their sets, you can learn how to handle it as well.

NOTE: I'm talking about situations where its fair-game (i.e. the guy isn't in a relationship with the girl).