No Jewelry and no clothes. IF you really really want to see him in a particular shirt/pants/whatever- then just buy him one. Not 'for" anything. Just becuase “I think you’d look hot/sexy/cool in this so I got you one”. Guys like that- but guys have long Proustian memories of getting clothes for Christmas and most of us never want anything like that again “for” an occasion. :eek:
You buy guys…toys. This includes hobby things, gadgets, and usually tools. Ok, I can see if he is into HobbyX and you find him a cool leather jacket with a pic of HobbyX on the back- that is pretty well out of "clothes-eww’ and into “toys- yay!!”
If he doesn’t have a specific hobby (or one where you can’t confidently buy something “cool”) then- A neat knife, a cool multitool, an expensive pair of sunglasses (Raybans, nothing too 'fashionable")- in other words- something he’d buy for himself but he won’t bring himself to spend the $$$ on it.
If he loves good port- then a bottle of port twice as expensive as what he has- same with singlemalt, etc.
A watch can combine “toys” and “jewelry” so some “swiss army” watch maybe or something along those lines. I saw this REALLY cool Swiss army watch that has three different light functions!!! 
A short FUN vacation also slips into “toys-yay!!”. If he still has a bit of innerchild, then Disney- or along those lines. Or a weekend trip to a nice hotel (on the beach?) with plenty of ooh-la-la, and a great dinner out.
Yes, indeed, if you want something really special, then a small inexpensive “toy” AND then a ribbon around your neck (“and anything you want me to do, dear”) can be a lot of fun for you both. If you can do massage- or even learn some few skills in a month or two- then a hour long hot oil massage followed by … isn’t bad either. (That small toy is still a good idea).
As for Spas- hmm, next B-day. Guys like spas if they have lots of long massages by female tech (nothing hanky panky is nessesary), saunas and any other kind of pampering by reasonable attractive females. Guys love being pampered (in a manly way, of course!). You could both go together even, for a weekend.
Note that I am considered a GREAT gift giver. I spoil my SO, and to a lesser extent, my freinds. I truly love giving cool presents. (I am no saint- i like getting them too!!
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Oh, and don’t waste a lot of time looking for “just the right card”. Most guys read them, think “that’s nice” and toss 'em in a drawer. In fact, you could skip a card, and most guys wouldn’t care (unless you are apart, then cards & letters are important!) Flowers? Eh, once in a while. After a great lovemaking session, delivered the next day to his work with “thanks for last nite!!!”- yes, that’d be nice. 