My sister-in-law recently went to the Missionary Training Center (MTC) in Provo to prepare for her mission for The Church of Jesus Christ of Latter Day Saints. Her first week in I sent her a "greenie" package. It was a great MTC gift, and didn't cost much.
Oftentimes, new missionaries are referred to as "greenies." I packed a box full of green-themed gifts to brighten her day.
I found Mike & Ikes, wintergreen life savers, mint oreos, and mint kisses to snack on. I also included a green canister of nuts in case she was in the mood for a healthy snack. Finally, I found green printed notepads, and cards with a green pen. Missionaries are always in need of tiny note pads to jot down appointments or notes, and cards to send notes to their friends and family.
This package was a huge success - she loved it!