What happens to care packages if the soldier isn't there to get them? Do they go to a chaplain? What can we do to make sure they get used?

some times on the Customs Declaration there is a place for alternate delivery instructions ... if it is there, mark where you want it to go to...
During the first desert war, I sent several packages each month to former troops and friends of mine in I always added a second address or to Unit Chaplin for Distribution...

All packages have to be properly addressed. However, quite a few of the packages that come out here will have a sections saying something to the effect of "if unable to deliver to (specific soldier), deliver to any service member"

I think a lot of it just depends on the local SOP. When I was in Iraq, some went to the Chaplains office, while others went to specific units/Soldiers. I can attest that shortly after getting in country, when my office would receive them.....from say some random grade school class, they were not addressed to any particular unit but handed out. Believe me, those packages never went to waste.