Realistic hanpainted textures

Hello, i’m starting journey with unreal and game development. I always liked stylish textures in games. And i(with programist friend) decided to create simple RPG, with painted textures. But problem is, I’m starting with painting and my textures looks bad and very toony. We want create dark RPG and these textures dont fit to it. Do you have any techniques for painting? Or maybe i should use photo textures, use filter for make it more blurry, then bake shadows and at the end draw some details? Tell me your secrets xD

Don’t paint any shading to textures. Let the light do its work. Stylised but realistic textures could be very low detail but clearly readable. You could even start with constant color textures and roughness textures. Physical based rendering does wonder with clean and noiseless textures. Such like Witness or Rime
These are easy to paint and you can even check that your values are physical based so those automatically look realistic. When you find look what you are after you can try to add more detail.