Hmm, well, if you don't mind some criticism: the ears look a bit lopsided on that hat. Second, maybe you shouldn't shade it by scribbling all over it. Instead, pick a light source then highlight the areas facing it and shade the areas facing away from it. If you want it to have texture, then you're going to have to use what we call dithering.

Dithering is not simply 'crosshatch' dithering, though. Irregularly shaped dithers can give the appearance of scales, or feathers or even fur. I could pull up a tutorial for it if you want.