hey there!
I am also a teenager, but I am running something a little different.
;)
What you can do is ask the people who donate what celebrity they want an autograph from.
then you can write to that celebrity and tell them about your cause (you will want to read the stickys) and request an autograph or something.

hello!

Ok so my question is, i am running blood drives in wisconsin and some teens my age thought that if they had a chance to possibly win a signed autograph from there favorite celeb they would possibly donate more. I really don't know about going by this, and there is a specific drive i would need autographs and such. I don't know how to word it or anything so this is me asking for help!!

thanks!