Deviantart’s definitely been on the decline, and the recent layout change seems to have done a huge number on them too. Perhaps they’re revitalize in a few years, but right now, ??? Not as much worth the time for me, honestly.
I’ve effectively given up on FB. Apart from my disagreements with the company/CEO, and that you have to pay to get people to see your posts, I just never really got any return from posting there. I know everyone and their mom raves about FB groups, but I haven’t gotten anything from those either.
Instagram doesn’t work for me, though that’s likely more so to do with the fact that what I post isn’t consistent, and IG only likes consistent content. I’ve found it /can/ help on various socials to ask questions to help bring up engagement. And I know IG likes it when you use Stories. Some advice I saw recently from a larger IG artist was to get rid of posts that don’t fit your theme or were unsuccessful. I hope this doesn’t come across as rude, but as an example on your page, something like this, while cute and perhaps relatable, doesn’t fit with the rest of your posts. I’d test out avoiding stuff like that for a while and see if there’s any improvement. This artist really stressed the important of mood/consistency/quality.
I’ve actually been having a little more success with Twitter (it’s been super slow growing lol), and I think a lot of it comes down to presentation. If an image is too tall, add two others to group it together to see the main image better. (Example) Can also be an excuse to show off different angles or close ups. (Example) The important part is just making sure the visuals can be clearly seen, and not hidden behind Twitter’s trash cropping. (IG is similar in that regard.) Having clean text in a post is helpful too. People hate reading, especially on Twitter, so I’ve found less text to work decently, depending on the context. Hashtags have recently become more irrelevant, as Twitter searches the whole post now instead, so that’s another thing to consider. I feel like we’re all used to hashtags, so having them in isn’t necessarily a deterrent, but I do like to keep them separate from my text to keep stuff clean.
I think you could still do some kind of video content though. Having some sparkly shots of your jewelry, or make a GIF of that, etc. Even some behind the scenes shots/time lapse of you working on something. 
Kind of just me blabbering, but hope at least something was useful out of it x’D Good luck!