For philanthropy day, we've done boo boo bunnies made from washcloths every year (complete with googly eyes & pink noses!) - theyre pretty easy to make, & the PNMs always think theyre cute
As far as promoting recruitment on your campus, if you have a student activities fair, having a table at that is a great way to show PNMs information about greek life. Also just being visible and active on campus before recruitment (to show that you have fun together as sisters) is a good way to promote a sorority. I'm not sure how the rules work on your campus, but personally inviting PNMs to attend your events (with letters in their mailboxes, etc) or posting flyers advertising recruitment could also be options for you.