A colored tie, and vest with different buttons is cool and unique.
Colored socks let the groom and his men wear their favorite colors and set them each apart a bit.
Mixing patterns adds interesting layers if the grooms a bit more daring.
The classic skinny black tie is just so hip.
Suspenders are a fun alternative to the classic belt and and mixing it with a floral shirt? Absolutely charming.
And the bow tie evokes the suave look of James Bond.