You CAN specify specific decorations, if you're willing to mod. I have a decoration workshop (lost the raws to datamonster) that has a few reactions, namely "encircle with bands", "spike menace", and "hang rings". These take 1 anything + 1 metal and produce a decoration on the "anything" of that type. So I can selectively place a masterwork steel helm and a bar of gold in a workshop, and produce 1 encircling, which results in the helm being encircled with golden rings 100% of the time. I haven't tried it for art images, because those are random and I'm not sure how it would handle those, but for other types, well, I had my militia commander decked in masterwork steel with hanging rings of iron and lead, because her squad was named "the chains of fleeing" or something like that, so I added a bit of shackles.
See the reaction for glazing pottery, it shows how to make a decorating reaction. Just be aware that if you're accepting anything, you can decorate odd things. "This is a pig tail roast. It menaces with spikes of jade." "This is a bar of lead. It is adorned with hanging rings of gold." You can also, theoretically, apply strange decorations. "This is a willow bed. It is encircled with rings of dwarven wine and menaces with spikes of dwarven syrup. On it is an image of a cat in charcoal."