Personally, I find that sharpness and simplicity define elegance. I like sleek, form-fitting Italian style suits, understated but attractive ties, a simple crisp clean white linen shirt, and a nice pair of shined black or very dark brown leather dress shoes. You can never go wrong with black, dark navy, or dark grey.
For semi-casual, I love form-fitted turtleneck shirts, again in black or navy. Couple this with a nice pair of dress slacks or light faded blue jeans and a nicely tailored black leather jacket or bomber. The leather jacket shouldn’t be the kind gangsters and juvenile delinquents wear (lol), but the kind that looks refined and professional, sort of like a dress jacket. This would also look great with a crisp white linen dress shirt or a light, baby blue dress shirt.
With jewelry, less is more. The person should wear the jewelry, not the jewelry “wear the person”. One nice ring on the index finger is enough. One elegant watch on the wrist is enough. When I see some of these guys wearing all those heavy chain necklaces or gigantic rings on almost every finger, or those big fake gold pendants, I want to regurgitate! Lol.
And just a small dab of cologne. I hate it when people douse themselves with designer fragrances (a lot of young guys like to do that), so much that you can smell them all the way to Iceland.