My chapter was on probation for low membership about a year or two before I joined. The one thing that we still talk about that they did to increase membership was to wear letters. They wore letters EVERYDAY from teh start of firstyear orientation through recruitment. Each night, they would meet at the house and trade. The feeling by the time rush started was that our house was huge, even though we only had about 15 affiliated sisters, because potential members had seen our letters everywhere.

Good luck!
Becky