I have to really look hard to find areas to improve as nothing is jumping off the screen to me, which is a very good thing :) So I have just itemized a few minor areas to focus on
- the direction of the fur on the cats back (not shoulder) could be slightly more curved upward at the tips of the fur and a bit more varied in length
- darkening the values slightly along the outer edge of the ca'ts back will give the illusion that his body is starting to curve back in and helps the viewer's eye stay inside the drawing area. This is a good trick in all drawings/paintings, having the outside edges slightly grayed down or darker so that the viewer's eye is drawn into the artwork
- his right paw angles outward in the reference photo and in the drawing angles inwards, chest fur is more curved downward in reference photo and softer, upper chest fur extends too far out on lower portion of neck and not far enough out on upper portion - these changes makes no difference if you are not looking at the reference photos but if you are doing a commission or more specific features (ie eyes, nose) this is something that you would want to take note of
- darkening the edge of his right cheek and adding a bit more of a curve will give more of a rounded shape to his head and create just a bit more depth & the dark markings on his body are not as wide in real life and form a bit of an arrow which gives the feeling of him crouching again adding more shape
- darkening the base of his ears slightly will give the illusion of the distance between the ear opening and the edge of his head (where I scratchily drew the circles in blue)
- darkening the top lighter area on his forehead (circled in blue) slightly will give more of a rounded shape to his head
His eyes and ears are done exceptionally well and the carpet and cast shadows look awesome! Again these are all really minor changes that would push this drawing to the next level if you wanted to have the cat's portrait as accurate as possible, say for a commission. Excellent job Sally!
The eyes are very expressive and warm and she has captured the wet glossy feel by having those really dark values against the bright highlights of the eyes. The darks are not flat black holes though, as they are several different values of darks which create more depth and shape, very well done :)
The line over the top of the nose indicates where the dark area of the nose has gotten a little too rounded, giving a heart shape feel. Softening and removing a bit of the curvature will give a more natural feel. The square above the nose or top area, shows where the lines have gotten just a little too linear and defined. Again softening and varying this area will give a more natural feel as well. These are all very minor changes and the drawing works just fine without these edits but pushing a little further will really make this portrait even more three dimensional.