Andre:
Some of the ladies here (like GraceUnderFire and Wheelie) have some really good points here. I would take the hint and listen. I especially liked how just a smile and taking the courage to walk over does work.
As a guy, one thing that has worked for me is just opening doors. A woman will often say “thank you” and give you a nice smile - it’s a way to show some familiarity and gentlemanly conduct.
Andre, if you want to approach someone after Mass, I would wait until I got out of the sanctuary (either in the narthex, the parish hall, the cafeteria, or outside). You can say something about the Mass, or you can say something about the parish. Try making some small talk. I have done this, and believe me, it is a good starting point for a conversation (it’s not a “pick up line”). I remember just meeting a nice lady after Mass by saying something about a homily that was given on the day JPII was canonized. I also met a nice lady one day who until recently I didn’t realize sang in the choir - I usually don’t attend the Mass where the contemporary choir sings.
I’ve also been able to meet some people after Mass that were sitting closer to me, where you can say “the priest did a good job. I liked how…” I also like the fellowship of coffee and doughnuts, and my Knights of Columbus council does a pancake breakfast about once a month. Coffee and doughnuts is a good, low key way to say hello to someone, have a little conversation, not spend much money, and there are others around.
Actually, I do advise more single men to take this initiative. Oftentimes, I hear women complain that not enough men attend church.
Hope this helps.