I have experimented with textures as well and I have created this more realistic look for the tree. But on a second thought I don’t think it works well with the overall style I have been working so far.
I then started adding elements in the background according to the painting.
After I started to create the sky assets: since the brushstrokes in this painting are visible and thick, I thought I could recreate them in 3D using a polygon modelled like a brush stroke to create the movement and resemble those in the painting.