I'm sure our school totally scammed this idea from another school, but here it is: Flamingo Insurance!
Basically, you send out letters / e-mails to faculty, pharmacists that your student group knows, etc. asking for a donation to your student group and call it "flamingo insurance." If the recipient of the letter / e-mail decides to not donate any money, they run the risk of getting their yard "flamingo-ed" (a group of students puts like 50 of those cheap plastic pink flamingos in that person's yard). Then, if their yard is flamingo-ed, you then ask for a donation for a "flamingo removal service."
This is all done in fun, and the letter / e-mail that goes out should always include a provision to opt out of the fundraiser, so that no one gets mad about having flamingos in their yard. The way you can do this is require the recipients to reply "yes I will donate" or "no, I realize I run the risk of getting flamingo-ed" so that you know not to touch the yards of anyone who did not respond at all.