Positive cheery notes are always welcome. I would go to the Dollar Store and buy a bunch of inexpensive but wacky cards, often with blank insides. I would try and clip out news articles from our hometown newspaper, church bulletin, etc. Lots of photos. He asked for some things, like velcro, so he could velcro everything in place in his footlocker, and his favorite footpowder (gold bond). Just stay positive, and remember that alot of the exercises they are going through may not make sense to us (civilians) but are designed as a weeding out and screening process to determine if the candidate should be an officer of Marines. Manufactured stress is a big part of that weeding process.
When is your candidate scheduled to graduate? Our very own Jonathan (GreenVolunteer) from Grits is currently at OCS. He classed up June 2nd I believe. I am in VA getting our house outside of Quantico ready to lease, so I am hoping to be able to attend graduation.
Good luck to you and your candidate. If you have any questions or need some support, feel free to PM or email me. Hang in there!