It always depends on what you send and how you send it.
If you wish to hide the contents or avoid custom duties, there is always a chance of things disappearing. If everything is listed and accounted for, much less chances.
I do not list everything, and sometimes intentionally do not list some things. For example, I know there is some weird regulation about sending books and information materials. So whenever I send books - I write something like "calendar".
I sent once few books to my professor to Ukraine, textbooks that she needed for the course. They were kept at customs for almost 4 months!! and in the end - they wanted to collect some customs charge from my professor, even though these particular books did not qualify for that specific custom charge. Both my professor and I were calling customs office and had lengthy conversations with them.
If I send several items of same type - I just list 1-2.
If I send anything that even vaguely reminds jewelry - I hide it in the pocket of some apparel. For any bigger items - I write in general terms "souvenir."
I send with USPS, in the graph "value" - always write "0", and add the phrase "gift, not for resale"
The regulations about sending food are constantly changing, so if I send chocolate - I list it as "souvenir" too.
In all the time - only 2 packages have disappeared. 1 - with rings for piercing that i sent to my friend, and another - with some designer clothes for another friend. Everything else arrived safe and quite fast.
Be mindful that Christmas in the Orthodox countries falls on Jan 6,7
if he sends the package now - most likely it will arrive around the early January to Ukraine. Since he lives at the East Coast. From the West Coast - add another week or so.