Lowpoly, handpainted trees and foliage assets with emissive maps so they glow in the dark. I made these to be used in a custom map in the game FeralHeart, which is where the last two pictures are from.
My Workflow:
Blender: Modeling, UVs
Substance Painter: Textures for the tree barks
Photoshop: Textures for the foliage and tree leaves