I think your forms are looking great for the most part!
My only nitpick I would say is I don't think your metals have enough contrast in them to really sell the metal look, which I know is probably a reflex from trying to make things not as (pardon the pun) black and white. This is something I've after noticing more so when doing miniature painting more so than any of my digital works that I've posted in my own topic and it's still something I'm working on figuring out myself so I can't actually post an example of my own to show what I mean.
From looking at your posts I didn't see any mention of the material study section (I may have just missed you mentioning it though) so if you haven't done that lesson yet I think looking at that would help you really punch up the metallics!
Overall though, I love a lot of your pieces and look forward to seeing more of them and seeing any further improvements you make along the way!