If you don't know of anyone that you can send stuff to, I suggest contacting the USO and/or local recruiters, who will be more than happy to give you blind FPO addresses for you to send general delivery parcels to. That way a unit can share whatever you send to them.
Don't try and send booze or OTC pharmaceuticals, and certainly nothing illegal.
If you want to send to someone serving and do not know who to send to, you an also go to anysoldier.com. Click on where to send to reach a searchable list of service men and women looking for things and what they can use. When I hae sent things, it has usually received a very positive response. Twice, I received no response.
One OTC pharmaceutical I've seen requested: stuff to fight foot fungus. I think it might make it through.