The hard part of buying for your father is that by the time you have money he has already bought himself everything he wants. So the useful category is not things he lacks. It is better versions of things he already uses.
The Christian travel bag
Classic, durable and roomy enough for a weekend without thinking about it. This is the single most given gift on our list, because a man who travels a few times a year is usually still using a bag he bought in a hurry a decade ago.
Small things he will actually wear
Accessories and ready to wear start at $100, which is the range where you can buy something good rather than something symbolic. The ivory popover shirt, the 3J Whisky Shot polo, the Soho sunglasses and the cream safari jacket are the four we recommend most often, and none of them require knowing his exact measurements.
The black merino turtleneck is the safe one. It is the piece nobody regrets owning.
When he really does have everything
Then buy him the appointment rather than the garment. A gift card puts him in the studio with a stylist and the cloth library, and he chooses. It solves the sizing problem and the taste problem at the same time, which no object does.
Every THEODORE garment is cut to your own measurements. Book an appointment at the studio, at a touring fitting, or over video.