Just as art can be given greater detail through a few small brush strokes, so too can an outfit be given greater detail with the addition of a few accessories. A hat or necklace can add a bit of color and shine to an otherwise drab outfit, while garters, sashes, and belts can break up solid blocks of color and add a bit of contrast.
Likewise, adding some jewelry like a ring and/or bracelet can show that your character has a bit of wealth, and even the poorest people “In Period” would’ve done their best to have some kind of jewelry to suggest that they had some degree of wealth and status. Glasses can also prove to be useful for completing an outfit–even if you don’t really wear them, a set with false lenses can add quite a bit to your kit.
Finally, satchels and pouches can add color and break up solid patches, while also adding dimensions to your outfit. They serve another purpose though–carrying capacity! You’ll need to carry all of your little props and tools somehow, right?