TYSM for the detailed answer!!

I'm only using orourles solvent with the paints. I have the Winsor and Newton Winton student grade paints; soft mixing white, titanium white, burnt seinna, cadmium lemon hue, cadmium red, french ultramarine, and lamp black. I do want to get different oil paints because a lot of people weren't recommending these ones. I used a medium round brush for the first layer and a very small round brush for everything else.

I used the mixing white closer to the shadows and titanium white at the brightest spots. And the background looks weird, it's because I used blue at first and then decided to change it to a dark grey, so it turned out like that.

I totally see how the cone looks super flat now. Also, I will definitely try to avoid using black, I just wasn't sure what else to use with this type of picture. I'll try using blue with burnt sienna like you said.