Welcome! You got some solid light work going on that first piece, I'm impressed!
My advice is to work more on your edges. Sometimes they're shaky, we can see the individual strokes, and they don't help with the final result because shaky edges make it look like if you were insecure when painting, even if you weren't. You can fix this sort of issue with lasso tool.
Also be careful with brushwork on areas that should be more discreet. Brushstrokes must mean something. There isn't much change on the collar's surface, and you don't need to add interest there because it's not a focal point, so sharp strokes look misplaced.
(open image in a new tab to better see the edge changes)
You can also:
- Work more on your materials. The candle stick doesn't look like wax, because you only worked the translucency of the melted part. A quick google search for refs can answer the question of how wax behaves in this situation. Same thing for the metal, it wasn't reflective, thus it looked like if made from the same material of everything else.
- Widen your color palette. You can do that doing loose studies from landscapes photos (nature has an insane amount of colors!).
On this artwork I acted as if the atmosphere was slightly blue: it makes sense, as the sky is blue, nights are dark blue etc; and it's convenient, because blue is complimentary to yellow on RGB chromatic circle. Yellow flame + blue atmosphere results in three possibilities:
· Blue. You'll want to do this mostly on pure white materials and reflections.
· Green, when you're dealing with yellow light + blue ambient light.
· Gray. You got some highly saturated reds and yellows going on there. Because colors are relative any gray will be perceived as a cool color, "bluish", when placed in the middle of this much yellow and red. You can use gray and it'll be perceived like as a discreet blue color. Do that when you want subtler combinations, when using blue would produce a too saturated image.
I used the three approaches on my overpaint to tackle different materials, and guide the composition.
I hope that helps!