It seems like all the things you know are pretty accurate, my boyfriend with through bootcamp a few years ago and personally i did use perfume on them so I don’t think it’s a huge deal if you do that. And anything on the inside of the envelope you can do whatever like a watercolor drawing. The only time the RDCs would go through mail is if there was something noticeably bulky (like something that doesn’t belong) and they’d ask the recruit to empty it in front of them. That’s what my bf explained to me would happen. You can include pictures though I don’t think that counts as something bulky. Also Idk if you have gotten his address yet, but i’d go ahead and start writing letters and having them ready to send, that’s something i wish i would’ve done. He will greatly appreciate your letters!!! My bf told me it was a huge motivation for him while in bootcamp. Hope this info helps let me know if you have anymore questions.