No paintover but if you want to learn rendering: 1. Do shading exercises of simple shapes like spheres and cubes in different light environments. 2. You can extend that exercise by shading those figures in the same style as Blizzard does 3. Do master studies. Pick an illustration in that style and try to replicate it. Not just mindless copy but actually asking questions: why did the artist do it? Why is here this color? Why is here a shadow and how was such effect achieved. It is also worth looking into the artists behind the official art and see if they have timelapses/courses and study those. 4. It does not have to be fruits but you will need to learn how to render different materials (wood, metal, skin, cloth etc). There are various tutorials on those - I would definitely look into it. 5. Looking at this piece you definitely need to work on edge control (look it up) and invest some time into color theory. 6. What can get lost - you also need to master tools. If Blizzard is your goal, look up what tools they require (usually photoshop and similar). It is worth learning those in the long run, too. Lastly, yes, I agree with your friend - drop textured brushes for now and practice with simple hard edge brushes. Then you can experiment.
