I've spent sort a lot of time figuring out how to print and polish metals. Just because it's neat. There was a LOT of trial and error, and very little actual material I could find reliably, so I hope this log helps any others (or future me) reproduce the results.
This is a quick overview for how to print metal filaments in a "normal" 3D printer: Colorfab (Brassfil, Bronzefil, Copperfil), Proto-Pasta (composite SS, Iron, and Copper), and Virtual Foundry (Filamet in bronze, copper, cluminum) sell filaments with at least 50% metal content. Other "metal" filament with less content can be printed like normal PLA (or whatever base plastic) and is therefore less challenging.
Now that you've successfully printed with "metal" filament, and possibly sintered a solid metal part, you want to make it look nice. These steps are generally chronological, but you can always go out-of-order or do a step again. If you do plan to sinter, I highly recommend a pass of trimming & shaping before the sinter, then further cleanup after.
Solid bronze can be finished and polished to a bright luster, not unlike jewelry. It's a very hard, beautiful metal with some cool properties. It cleans up similar to metal-filled plastics, but there are a few steps specific to solid metals.
tl;dr: pickle, brush, shape, tumble, maybe brush again, polish, buff, wax.