Whenever possible, find a woman to do the job
We hate to conclude this way, but we'd be lying if we left out this fact: Women make superior pick-up pals. One woman can easily chat up another and effortlessly lower the other's guard. Hell, she can even directly address her role as wingwoman to another woman, and still snag your boy an introduction.
A wingwoman's effectiveness boils down to two things:
1. Women will inherently trust a strange woman over a strange man. If two women hit it off, and the wingwoman vouches for the guy, he's been given a shot. No questions asked. Just enjoy the opportunity.
2. Aside from another woman's seal of approval, approaching a female with another woman may incite her jealously, or ignite her competitive nature, both of which will make you appear more desirable.
So, when in doubt of your ability to take one for the team, have an attractive, friendly woman in tow. Chances are, she'll be twice as effective and with half the effort. Sorry, guys.