Sometimes gift-giving is hard.
Especially when your loved one has absolutely everything.
This is the age-old question of the season: "What do you get someone who has everything?"
The answer that I propose is "something that makes a memory or reminds him of you."
A gift doesn't need to be vital to someone's existence in order to be appreciated. For example, one of the most prized possessions you can own are pictures, which--strictly speaking--are completely unnecessary.
A few other thoughts to get your mind going:
Give the gift of time--a baked treat, a long afternoon visit, a trip to your loved one's favorite restaurant (with your phone off and your attention fixed on him or her).
Give a subscription. It doesn't really matter what type of subscription--magazine, newspaper, video streaming--whatever your loved one is interested in. This is the gift that keeps giving all year long.
Give a shopping spree. Have something vague in mind, take them shopping, and let them pick what they want. This will give you sweet memories of time well spent and also give them something by which to remember the time.
Give a book or a video. This gift can give hours and hours of enjoyment without taking up valuable real estate in their house/apartment/room.
Give an experience. One of those paint-and-fire pottery places, a drive to see Christmas lights, a craft night.
There are lots of good gift ideas out there, but sometimes it takes a little thinking outside the box. I hope I've got your mind turning with ideas that will precisely suit your loved one.