In short: The best gift for a husband is a quiet one that carries a small piece of your story, such as a date, a number, a place or a handwritten line. Choose the nicer version of something he already uses, so he wears it on an ordinary day. Only the two of you need to know what the detail means. It works for a birthday, for Christmas and for an anniversary.
Start with what he doesn't buy himself
Most husbands buy what they need, when they need it. What they skip is the nicer version: the sweater, the leather piece, the thing that simply feels good. That gap is where a gift lives.
Hide your story in a detail
A date, a number, a set of coordinates, a handwritten line. Only the two of you know what it means. That is what turns a purchase into a gift.
Keep it quiet
The best gifts do not shout that they are gifts. He can use it on a normal Tuesday, and he will know where it came from.
Works for any occasion
Birthday, Christmas or anniversary: a quiet gift with a private meaning fits all three.
Not sure about the size?
Compare with something he owns, and look for a free exchange period.
More ideas: The Gift Nobody Else Will Give Him.
A note on transparency: we make a cashmere sweater ourselves, limited to 25 numbered pieces, so a number can carry a meaning. The ideas above work for any brand. Our sweater is one of many you can compare.