Good
We had "secret sisters" in addition to our Sis-Moms. These secret sisters were responsible for sending good thoughts to the NMs via cards, poems, or notes during the NM period. For Initiation Day she was the one who made the keepsake box for the new initiate.

Bad
First of all, calling them pledges. I was a pledge as it was called "pledge" then, but it's not the same anymore.

Requiring the NMs to address the initiated sisters by something other than her given name and being forced to address initiated members in a certain way should you come in contact with them. (for example, you see Suzy Sister across campus and you run up to her and you're required to greet her "Good morning, Miss Suzy Sister you're looking beautiful today") -- I see this done all the time