A couple more tips for ya...
Servicemembers have been instructed not to open mail from unknown senders. I fear that any packages sent to "any soldier" may be discarded.
Ideally you would want to send it to a specific soldier who knows it is coming.
You can do this by sending post cards to "any service member" first and offering care packages and requesting instructions on how best to send them. It's also important to have a specific address because the mail handlers, however unfortunate, will hoard the goods for themselves. I speak from experience.
You can also get specific names and addresses thru family, friends and perhaps any local military bases.