When I was a freshman at a college, my great Aunt Doris randomly sent me a couple of Halloween decorations in the mail in October. It's always fun to get mail when you're away and her little package came right around the time that the excitement of being away from home for the first time was wearing off and some homesickness was sinking in. It was just a couple of silly paper decorations but it really stuck with me how it made my day.
So when some of my favorite nieces were away at college, my son and I started the tradition of sending them Halloween care packages every year. It was also a great chance for me to get him excited about doing something for someone else and also to talk about family and what college is. Somehow we started trying to include some spooky stuff in our packages - like fake eyeballs and fingers - and every year we tried to outdo ourselves.
You can really include anything you'd like. To throw out a few ideas - we also like to include candy, decorations, some homemade cookies, snacks, etc. My nieces always seemed to like it and the pic on this post is actually one I copied from a Facebook thank you that one of my nieces posted. It's just a fun way to pay it forward from my Aunt Doris.