I just thought about this and I think I have a great one.
I bought really nice clothes for skit day at one sorority during informal. I looked good, I thought. I sat next to another PNM who turned to me and said "I love your pants, where did you get them?"
So I told her. I bought them at Old Navy. I'm pretty sure that got me cut. That sounds dumb, but I found out later from a reliable source that this sorority totally judges you on what you wear. It's all good though, I wound up in the right chapter. And that PNM? She became a pledge sister (but unfortunately couldn't complete the process. I miss Julie
)