There are two flat-rate priority boxes you can use:
Cubes and rectangles. Cubes were used 100% for OCD last year to ensure that a soldier didn't appear to get more goodies than another.
Both boxes cost the same to ship (less than $9): one is deeper (cube) while the other is flatter and longer (rectangle). If you wanted to make a 9x11 pan of brownies and just pack the entire pan in it, use the rectangular one.
Metal tins are permitted.
Pack your box solid with packing material or goodies, seal it well, then drop it. Go ahead...drop it. You have to feel confident that whatever you've packed can handle that kind of abuse.
You can ask your mailman to bring an empty FLAT RATE Priority box directly to your home.
However, since you have to submit the 4-part customs claim with it, they can't pick them up at your home (at least my PO won't do it).
According to the www.usps.com website, the last day for Priority shipments to overseas military (and still meet Dec 25 deadline) is
December 11th.
One final thing...I added a Delivery Confirmation tag to each OCD box last year (~$1.50 per box). Out of 41 boxes sent, only a few boxes actually logged in the delivery data online, even though we know the boxes all got there. It's your call if you want to pay for that option. I thought it would be a great idea, but it didn't pan out very well. Maybe they've gotten better at it.
http://shop.usps.com/webapp/wcs/stores/servlet/ProductCategoryDisplay?catalogId=10152&storeId=10001&categoryId=13359&langId=-1&parent_category_rn=11820&top_category=11820
