Wow, and I was kidding. But, they do help (and look nice and anonymous).
Suggestions:
-Some kind of belt, probably black would be best. It'll probably be hidden by your shirt most of the time, but might be visible every now and then.
-A watch would probably help too. I think any black coloured or leather watch would work better than a silver one, but silver might work as well. Also, as you said, one with a wider strap.
-As you said, a large print tee might help as well, depending on the placement. I would recommend one with a light design, rather than one with a bold design.
-It's too easy to look like a poser with leather cuffs so I usually avoid them. Maybe you can pull it off without looking like a poser, though.
-I can't imagine a necklace looking good with the current style. But who knows, if you can pull it off maybe you'll "invent" a slightly new style!