First serious attempt at trying to make photo-realistic cycles textures.
Any suggestions or advice on improving it?
Looks real - in all three scenes.
My question yo you: what do you want to achieve with the composition?
Certainly looks like a glass vase; in the first composition, it looks like some type of ceramic or pottery.
The steel ball is superfluous.
I’d check out the ‘rule of thirds’ - google it. That would, imo, improve any of the images. Tough to make something more real than looking real. 
I agree with Writer’s Block that its hard to make things even realer than they allready appear!
One thing you could improove, is the table benaeath i think. Because it’s bright colour/texture it seems to me like a temporary built up table at a construction site, if that makes sense
In this HDR/backround I think a more processed table would suite more to the style of the place one can see in the back and would make it perfect. More than it allready is