I send ONE box. I use boxes like these (http://www.officemax.com/omax/catalog/sku.jsp?skuId=21135380&searchString=&productId=ARS22935&category_Id=664), only not that size (pick the smallest size that will hold a ball). Put some double-sided foam tape on the outside of the box such that the player can remove the backing and seal the box back. When YOU close it, just use some packing tape to secure the front flap (so the flap goes over the foam tape). So, instead of tucking-in the flap, leave it on the outside. Include a postage-paid self-addressed label that the player can peel off and cover up the label already on the box. I hope this makes sense. Let me know if I need to clarify anything. I use the padded envelopes. I address one to whom I'm sending to and the other with my address on it. I put my baseball, pen and note inside a zip-loc bag. The ones with the white tab to open and close with. I fold the padded envelope in half and add the zip loc bag and send. I put 5 stamps onto the return envelope and take the package to the post office to pay to ship. Here's 2 different ways to choose from. Pick what you like.